Abstract
Literacy is crucial for academic, social, and personal development, yet individuals with intellectual disabilities (ID) often face significant cognitive, linguistic, and educational barriers. This may be exacerbated within bilingual contexts. This scoping review focused on mapping recent literature on literacy practices for bilingual learners with ID. The scope was to identify effective instructional strategies and possible barriers to literacy intervention. The search included empirical studies on literacy practices in ID within bilingual/multilingual settings, published between 2020 and 2025. Eighteen studies met the inclusion criteria and were analyzed descriptively. The analysis revealed six thematic areas: family-driven bilingual literacy, educator experiences, cross-linguistic learning, evidence-based literacy instruction, innovation in literacy tools, and inclusive bilingual education settings. Findings indicated the benefits of bilingual literacy instruction, specifically in cross-linguistic transfer effects in phonological awareness and decoding. However, systemic barriers were also identified. These included inadequate educator preparation and over-reliance on monolingual assessments. The review highlights the potential for inclusive, linguistically diverse interventions. Future research should explore holistic, collaborative, and methodologically diverse evidence-based approaches to stimulate better skills and implement effective practices for multilingual learners with ID.
Introduction
Academic achievement, social participation, and individual growth depend heavily on literacy skills. Reading and writing abilities are important for individuals with intellectual disability (ID) because they facilitate better communication, enhance independence, and improve overall well-being (Burgoyne et al., 2016; Cioè-Peña, 2020). Individuals with ID experience early-onset neurodevelopmental deficits characterized by significantly impaired intellectual and adaptive functioning, typically indicated by an IQ of 70 or lower (Lee et al., 2023). Individuals with ID experience recurring obstacles during literacy learning due to possible cognitive limitations, language barriers, and physical disabilities. However, physical characteristics are not the only barriers to successful literacy development in individuals with ID. Barriers to literacy learning also exist within educational practices and societal perceptions.
Pesco et al. (2016) highlighted that special education policies often lack explicit guidance on second-language instruction, leading to inconsistencies in home-language support across regions. For example, Malta’s inclusion policy promotes access for all learners but lacks clear guidance on implementing IEPs or adaptive teaching (European Agency for Special Needs and Inclusive Education, 2022). Similarly, Australia’s New South Wales policy outlines inclusive goals but provides limited direction on teacher roles or practical implementation (Audit Office of New South Wales, 2024). Equally, de Valenzuela et al. (2016) identified structural issues, such as prioritizing remedial services over language instruction, scheduling conflicts, and limited resources, which consistently restrict students’ access to bilingual literacy opportunities. Existing literature reviews (e.g., Liu et al., 2020; Rivera et al., 2021) confirm these systemic challenges, highlighting the dominance of monolingual practices in the U.S. context and the scarcity of research on bilingual literacy instruction for learners with ID. These systemic gaps highlight how institutional decisions can directly affect literacy development among bilingual learners with ID.
Within this broader context of literacy access and policy, bilingualism introduces additional considerations for learners with ID. Bilingualism is typically defined as the regular use and understanding of two distinct languages, involving functional communication across different linguistic systems in everyday contexts (Tiv et al., 2021). Bialystok (2018) and MacLeod et al. (2016) link bilingualism to cognitive and sociocultural advantages, including enhanced metalinguistic awareness, stronger identity development, and improved cross-linguistic transfer of literacy skills. Although these benefits are supported in typically developing populations, educators often approach bilingualism with caution in relation to individuals with ID (Ware et al., 2015). Although the value of bilingualism and biliteracy is increasingly acknowledged, much of the research continues to center on monolingual perspectives and English-dominant ideologies in special education contexts (Ferrell et al., 2024). Instructional and assessment practices often fail to capture the full linguistic repertoires of bilingual learners with ID.
Professional decision-making plays a central role in shaping bilingual literacy experiences for learners with ID. Educational choices made by educators, therapists, and policymakers can exacerbate learning barriers, particularly in bilingual and multilingual classrooms. Marinova-Todd et al. (2016) highlighted a divide between educators’ positive beliefs about the bilingual capabilities of students with disabilities and actual educational practices. Despite acknowledging that bilingualism is achievable for these learners, bilingual students with disabilities often receive fewer language supports, with institutions frequently offering English-only interventions or limiting access to specialized bilingual services. Such decisions are influenced by broader contextual constraints, including restrictive language policies, limited educator preparation in bilingual special education, and insufficient availability of culturally and linguistically responsive materials (Marinova-Todd et al., 2016; Pesco et al., 2016). In bilingual communities where diglossia is present, the interplay between languages can further complicate instructional decisions, leading educators to prioritize the academic language due to assessment demands, perceived utility, or limited training in bilingual pedagogies (Panzavecchia, 2024).
These professional and structural choices have implications for how bilingual learners with ID participate in literacy learning and in school communities more broadly. Emergent bilingual students with ID remain one of the most overlooked groups in educational research and practice (Rivera et al., 2021; Soto-Boykin et al., 2023). Although evidence indicates that bilingualism does not hinder literacy development in neurodivergent populations (Kay-Raining Bird et al., 2016; Marinova-Todd et al., 2016; Ware et al., 2015), decisions to prioritize a single language in educational settings can carry social and cultural consequences. When home languages are excluded from literacy instruction, learners may have reduced access to culturally meaningful literacy experiences and fewer opportunities for identity development, engagement, and participation within classroom communities (García & Kleifgen, 2020).
Marginalization can occur when learners are systematically excluded from full participation in educational opportunities and decision-making due to structural, institutional, or normative practices that privilege certain linguistic, cultural, or cognitive profiles over others (Slee, 2011). For learners with ID, this marginalization is often reinforced when they are viewed primarily through a disability lens, overlooking the intersectionality that reflects their linguistic and cultural identities. Such perspectives are frequently informed by structuralist linguistic beliefs that sideline home languages and reinforce deficit-oriented assumptions (Leung & Molnar, 2025; Muscat, 2025; Rivera et al., 2021). These approaches contribute to misjudgments of learners’ capabilities, overidentification for special education services, and continued reliance on standardized monolingual assessments that do not adequately reflect bilingual development (Ferrell et al., 2024; Leung & Molnar, 2025).
Growing research in typically developing populations supports the provision of foundational literacy instruction across languages, given the strength of cross-linguistic transfer (Zhang et al., 2025). This is not always reflected in educational settings for individuals with ID, where monolingual approaches have historically been prioritized. Such preferences have been shaped by long-standing assumptions that bilingual literacy may hinder development, as well as concerns regarding the cognitive demands of managing two languages (Kay-Raining Bird et al., 2016; Kormos & Smith, 2023; Marinova-Todd et al., 2016). However, empirical evidence suggests that emergent bilingual students with moderate ID can benefit from instruction that incorporates their primary language, particularly when literacy instruction is systematic, explicit, and linguistically responsive (Kay-Raining Bird et al., 2016; Rivera et al., 2021). Research highlights that instructional approaches integrating systematic and explicit methods with culturally responsive techniques, including primary language support, significantly enhance literacy acquisition for emergent bilinguals with moderate ID (Rivera et al., 2021). Such multilingual interventions have also been associated with improved comprehension, reduced stress, and enhanced academic participation (Rivera et al., 2021).
Despite these emerging findings, research examining literacy practices for bilingual learners with ID remains limited and fragmented across contexts. Building on previous reviews (Liu et al., 2020; Rivera et al., 2021), this scoping review makes a unique contribution by synthesizing evidence beyond mainly U.S.-focused contexts to include international research on literacy development in multilingual learners with ID. Unlike earlier syntheses that primarily centered on intervention studies in self-contained classrooms, this review explores a broader range of literacy practices, including home-based strategies, technology-assisted approaches, and educator perspectives across various educational systems. In this review, literacy practices are conceptualized not only as instructional approaches targeting discrete reading skills (e.g., phonological awareness, decoding, comprehension) but also as the pedagogical, institutional, and linguistic conditions that shape access to literacy instruction for bilingual learners with ID. This broader framing reflects evidence that educator decision-making, language policies, and inclusive practices directly influence the quality, language choice, and intensity of literacy instruction provided to this population.
In light of these complexities, this scoping review aims to examine the existing literature at the intersection of literacy, ID, and bilingualism. Drawing on empirical studies, the review seeks to identify effective pedagogical approaches, contextual dynamics, and equity-related issues that shape literacy development in this population. This review also aims to contribute to the development of inclusive, context-responsive literacy models that challenge reductive conceptions of both language and disability (Ferrell et al., 2024; Leung & Molnar, 2025).
This review was therefore guided by the following research questions:
Which instructional strategies and literacy practices have been implemented to support the development of specific reading skills among individuals with intellectual disability in bilingual or multilingual contexts?
In what ways do these instructional approaches address the linguistic, cognitive, and developmental characteristics of learners with intellectual disability within bilingual education contexts?
What contextual elements influence the planning and delivery of literacy instruction for bilingual learners with intellectual disability?
Method
This study used a scoping review methodology, drawing on the framework developed by Arksey and O’Malley (2005) and later refined by Levac et al. (2010). This approach is widely adopted for reviewing emerging or dispersed literature, such as research into reading interventions for individuals with ID across multilingual contexts. It enables a comprehensive examination of existing data, facilitating the identification of current practices, thematic patterns, and areas that require further investigation. The review was registered through the Open Science Framework ref: DOI 10.17605/OSF.IO/QTBWG.
Search Strategy
A comprehensive and systematic search was conducted across multiple databases, including Scopus, PubMed, ERIC, Google Scholar, and EBSCOhost. The search included peer-reviewed journal articles, dissertations, and conference proceedings published between 2020 and 2025 to capture the most recent developments in the field. The authors decided to limit the review to articles from these years due to the progressive shift in the literature. Recent literature indicates a growing consensus that bilingualism does not disadvantage individuals with ID (Hwang et al., 2022; Muscat & Grech, 2024; Przymus, 2023) and, in many instances, it is advantageous. The database searches can be accessed through Table 1.
Database Searches.
The methodology of this review was guided by clearly defined inclusion and exclusion criteria to ensure the selection of relevant and high-quality studies. The inclusion criteria focused on studies that examined reading practices targeting bilingual or multilingual individuals with ID. Specifically, eligible studies included those involving participants with conditions such as autism spectrum disorder (ASD), Down syndrome (DS), Williams syndrome, or global developmental delay, where reading interventions had been implemented. Studies were included if authors identified participants as having ID; specific IQ ranges were not used as an inclusion criterion, as several studies relied on educational or clinical classifications rather than standardized IQ reporting. Studies involving participants with ASD were included only when ID was explicitly reported or when participants were described as having extensive support needs consistent with ID. Where studies included participants with multiple or co-occurring diagnoses, only data explicitly reported for participants with ID were evaluated. No restrictions were applied based on ID level (e.g., mild, moderate, severe), as the degree of ID was inconsistently specified across studies. The population of interest ranged from early childhood to school age, covering approximately 3 to 20 years of age.
Literacy practices of interest were those designed to enhance specific literacy skills, including phonological awareness, vocabulary development, reading fluency, reading comprehension, technology-based practices, and home literacy practices. Studies examining educator practices or institutional decision-making were included where these factors directly influenced the planning, language choice, or delivery of literacy instruction for bilingual learners with ID. Only studies conducted within bilingual instructional or home settings were considered, reflecting the focus on bilingual education. Empirical studies employing qualitative, quantitative, or mixed-method designs were eligible for inclusion. Studies from an international context were included; however, studies had to be published in English, as the main available literature is in English and due to the researchers’ limited language proficiency.
Exclusion criteria were established to further narrow the scope and exclude studies outside the scope of this review. Research focusing solely on populations with disabilities unrelated to intellectual or developmental challenges, such as sensory impairments, specific learning disabilities without ID, or physical disabilities, was excluded. Similarly, practices that did not target literacy or reading skills, such as those addressing mathematics, behavioral issues, or general language skills, were not considered. The review also excluded theoretical, opinion, or conceptual articles that lacked empirical evidence, as well as policy papers or reviews that did not reference original research data. Information on assessment tools was extracted where reported; however, the normative basis of assessments (e.g., monolingual or bilingual norms) was not consistently specified across studies and was therefore not treated as a formal inclusion or exclusion criterion.
The data extraction process was carried out by one researcher and subsequently validated by a second researcher to ensure accuracy and reliability. The second researcher read article summaries to ensure that the inclusion and exclusion criteria were applied and verified. A predefined extraction template was used to standardize the collection of relevant data across all studies, promoting consistency in the review. The study selection process followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, ensuring a structured and transparent methodology.
The first stage of selection involved a title and abstract screening, during which one reviewer independently evaluated the relevance of each study against the predefined inclusion and exclusion criteria. A second reviewer screened and validated the list retrieved from the first stage. In the second stage, full-text articles identified as potentially relevant during the initial screening were thoroughly examined to confirm their eligibility. Any disagreements between the two reviewers were resolved through discussion.
Results
Overview of Studies
Figure 1 illustrates a PRISMA flowchart, showing the number of studies identified, screened, and finally extracted.
PRISMA flowchart.
The total number of studies extracted for final evaluation in this scoping review was 18. All studies were deemed suitable as they examined intersections among bilingualism, disability, and literacy. The included studies employed varied methodological approaches, comprising qualitative designs (n = 6), quantitative designs (n = 6), mixed-method approaches (n = 4), and single-case experimental designs (n = 2). Table 2 provides a summary of the studies extracted for the review, illustrating the participants in each study, the literacy area addressed, the research design used, and aspects of reliability, validity, and bias control employed. The table is organized according to date of publication and alphabetically. Ten of the 18 studies were published in peer-reviewed journals, while the remaining eight comprised doctoral dissertations and conference proceedings.
Summary of Studies.
Note. D = dissertation, DS = Down syndrome, JP = journal publication, ASD = autism spectrum disorder, DLL = dual language learners, IPA = interpretive phenomenological analysis, CP = conference publication, MLL = multilingual learners, MTSS = multi-tiered systems of support, ML = multilingual, LD = learning disability, LSEN = learners with special educational needs.
A wide range of stakeholders and populations were represented in the selected studies. Perspectives included those of parents and caregivers (Gilhuber, 2023; Muscat & Grech, 2024; Washburn et al., 2023; Yang, 2023), educators and educational specialists including teachers, school psychologists, and educational administrators (Grande González et al., 2025; Li, 2022; Lim, 2021; Muscat & Grech, 2023; Shand, 2024), as well as students and learners with diverse educational support needs who often formed the direct focus of intervention research (Cersosimo, 2023; Forney-Misuraca, 2020; Frates et al., 2022, 2024; Larsson et al., 2025; Martin et al., 2021; Muscat & Grech, 2026; Regalla et al., 2024; Ward & Sanoudaki, 2021). Participants predominantly consisted of children and adolescents aged between 3 and 18 years, spanning a variety of educational stages including preschool (Gilhuber, 2023; Regalla et al., 2024; Washburn et al., 2023; Yang, 2023), elementary (Cersosimo, 2023; Forney-Misuraca, 2020; Li, 2022; Lim, 2021), middle to senior school levels (Muscat & Grech, 2024; Ward & Sanoudaki, 2021), and secondary education (Grande González et al., 2025; Larsson et al., 2025; Li, 2022; Muscat & Grech, 2023, 2024, 2025; Shand, 2024). Most of the child participants were bilingual or multilingual, typically speaking English and a heritage language such as Spanish, Chinese, Maltese, Welsh, French, Italian, or German. Reported disabilities among participants included ID, ASD, DS, learning disabilities (LD) with comorbidities, and extensive support needs. In all cases, analyses and interpretations were limited to findings explicitly reported for participants with ID or where ID was identified as a primary or co-occurring condition.
Thematic Groupings and Key Findings
The identified themes reflect both skill-focused literacy instruction (addressing Research Questions 1 and 2) and contextual factors that influence the planning and delivery of literacy instruction in bilingual settings (addressing Research Question 3). Accordingly, some themes capture instructional content, while others examine professional practices and systemic conditions that mediate access to literacy learning for bilingual learners with ID. Six distinct thematic categories emerged from the analysis. Table 3 provides a summary of the studies, subdivided by theme. A few studies could be classified into more than one theme.
Subdivision of Studies Into Themes.
Note. ASD = autism spectrum disorder, DS = Down syndrome, TD = typically developing, MTSS = multi-tiered systems of support, EB = emergent bilingual, ML = multilingual learner, LD = learning disability, ID = intellectual disability, HLE = home literacy environments, PA = phonological awareness, VR = virtual reality, LSEN = learners with special educational needs, EF = executive functioning, L2 = second language.
The theme of family-driven bilingual literacy was identified in four studies (Gilhuber, 2023; Muscat & Grech, 2024; Washburn et al., 2023; Yang, 2023). Findings from these studies highlight the importance of familial choices in language and literacy acquisition. A review of the studies identified that families use several strategies within the home setting to support biliteracy. The strategies identified included dialogic reading, translanguaging, and culturally situated literacy routines. Although resource constraints were identified, families from these studies demonstrated considerable adaptability, particularly in supporting children with ASD. Three studies (Gilhuber, 2023; Muscat & Grech, 2024; Yang, 2023) evaluated the home environments and practices; however, one study (Washburn et al., 2023) took a step further by providing interventions within the homes.
Five studies were identified under the theme of educator experiences (Grande González et al., 2025; Li, 2022; Lim, 2021; Muscat & Grech, 2026; Shand, 2024). Although these studies did not examine discrete literacy subskills directly, they provided empirical insight into how educators’ knowledge, beliefs, and agency shape the planning and delivery of literacy instruction for bilingual learners with ID. In particular, the findings illustrated how decisions related to language use, assessment practices, and inclusive placement influence learners’ access to reading instruction and literacy-rich learning opportunities. A recurring issue across these studies was the limited preparation educators reported receiving in bilingual special education, alongside restricted access to culturally responsive resources. Educators consistently highlighted the need for clearer guidance in assessment and intervention processes, noting that existing assessment tools and policy frameworks were often inadequately aligned with the linguistic profiles of bilingual learners with disabilities.
Cross-linguistic learning was identified as a theme of focus in five studies (Forney-Misuraca, 2020; Martin et al., 2021; Muscat & Grech, 2024, 2025; Ward & Sanoudaki, 2021). These studies addressed bilingual literacy development among learners with DS and ID. Results from these studies challenge misconceptions regarding the potential negative impacts of bilingualism. Findings demonstrate positive cross-linguistic transfer effects, particularly in phonological awareness and decoding.
Evidence-based literacy instruction was implemented in four studies (Forney-Misuraca, 2020; Frates et al., 2022, 2024; Washburn et al., 2023). The identified studies focused on structured, multicomponent reading programs. Interventions, including shared reading, explicit phonics instruction, and native-language supports, showed consistent development in literacy skills such as phonemic awareness, vocabulary, decoding, and comprehension. These were also associated with high levels of social validity, as reported by parents and supporting staff.
Innovation in literacy tools was a theme identified in two studies (Cersosimo, 2023; Larsson et al., 2025). These studies highlighted the usefulness of visual scaffolding techniques, such as graphic organizers and symbolic systems. Within literacy education, innovation can be understood as the application of new or enhanced practices or technologies, including multimedia storytelling, virtual reality environments, and multimodal symbolic systems, which extend meaning-making beyond traditional print-based methods and foster inclusive learning (Sharp, 2014). The studies also highlighted the impact of innovative technological solutions, including virtual reality and digital storytelling. The results showed that these methods effectively enhanced learner engagement and comprehension, providing alternative literacy pathways for students with ID.
A final theme that emerged was that of inclusive bilingual education settings, found in two studies (Martin et al., 2021; Regalla et al., 2024). Both highlighted inclusive language immersion contexts, such as a French immersion program. Findings indicated that differentiated instructional strategies and executive functioning supports facilitated successful participation and learning outcomes for children with ID; the two studies advocated for broader access to inclusive bilingual educational models.
The evaluation of studies also enabled the identification of the various instructional modalities used with individuals with ID. A synthesis of the studies revealed several modalities that were frequently employed. These included phonological and phonics-based instruction (Forney-Misuraca, 2020; Muscat & Grech, 2026; Ward & Sanoudaki, 2021), shared and dialogic reading approaches (Gilhuber, 2023; Li, 2022; Martin et al., 2021; Regalla et al., 2024; Yang, 2023), visual literacy and scaffolding tools (Muscat & Grech, 2023; Regalla et al., 2024; Washburn et al., 2023), technology-enhanced literacy interventions (Regalla et al., 2024; Washburn et al., 2023), explicit teacher-guided strategy instruction (Regalla et al., 2024; Washburn et al., 2023), and home and community-based literacy practices (Li, 2022; Martin et al., 2021; Muscat & Grech, 2024; Washburn et al., 2023; Yang, 2023).
Discussion
This scoping review was set out to explore current evidence on bilingual literacy instructional practices for learners with ID. The 18 studies reviewed provided diverse and meaningful insights into how literacy is supported and developed across linguistic and cognitive spectrums, reflecting a shift from deficit-based models to more inclusive and intersectional frameworks.
A key finding across the included studies was the broad diversity of participant perspectives, with research focusing not only on learners themselves but also on parents, teachers, and other practitioners. The diversity of voices reflects an evolving understanding that literacy development in multilingual learners with disabilities is not an isolated process, but rather a context-dependent one. An overlap of instructional strategies, family choices and needs, professional beliefs, institutional structures, and sociocultural values shapes literacy outcomes. Thus, the reviewed studies indicated that contextual and instructional factors play a central role in mediating literacy opportunities for bilingual learners with ID. Conceptually, this challenges learner-deficit models that locate literacy difficulties primarily within the child, instead supporting ecological and sociocultural frameworks in which literacy development is understood as distributed across home, school, and policy contexts. Hence, bilingual literacy development in learners with ID is positioned in a relational and systemic process rather than an individual limitation.
Parental perspectives emerged as a source of knowledge and practice. Studies exploring home literacy interventions (Gilhuber, 2023; Muscat & Grech, 2024; Washburn et al., 2023; Yang, 2023) demonstrated how families actively constructed literacy-rich spaces through shared reading, translanguaging, and everyday storytelling. For example, Yang (2023) found that Chinese Canadian parents of children with autism used Mandarin to adopt an emotional connection while simultaneously supporting English-language texts to align with school expectations. Similarly, Gilhuber (2023) and Muscat and Grech (2024) documented how multilingual parents incorporated print routines into their daily lives, even in the absence of formal training or external support. Muscat and Grech (2024) reiterated that parents often made different language choices in contrast to the language of literacy instruction utilized in the school. Washburn et al. (2023) further extended this theme by highlighting how multilingual families of preschoolers with ASD used multimodal communication, including gesture, visual supports, and home language use, to support emergent literacy. Their study emphasized the importance of recognizing family-created literacy ecologies that incorporate both oral and visual modes of expression, especially when conventional literacy practices may not align with a child’s communicative profile. These studies affirm the importance of building on the linguistic resources found in the home and of guiding caregivers based on updated, evidence-based practices. These findings extend existing models of home literacy by demonstrating that multilingual families of children with disabilities actively adapt literacy practices to meet both linguistic and communicative needs. This challenges assumptions that families require formal training to support literacy development and instead underscores the value of recognizing parents as knowledgeable agents within bilingual literacy ecologies.
From the professionals’ perspective, educators and support staff offered critical insights into systemic and instructional challenges. Li (2022) and Shand (2024) found that teachers often struggled to distinguish between language acquisition needs and learning disabilities, particularly in settings without coherent guidance on dual-language instructional planning. Lim (2021) extended this discussion by showing that teachers in dual-language K–5 programs frequently relied on their own discretion when making instructional decisions, leading to inconsistent implementation of translanguaging practices. The absence of clear policy frameworks or structured professional development left educators to navigate complex language and literacy demands on their own, often amplifying disparities in support for multilingual learners with disabilities. These findings contribute to an ongoing debate regarding the misattribution of difficulties in multilingual learners, suggesting that systemic ambiguity and professional uncertainty, rather than bilingualism, often reinforce inconsistent identification and support practices.
Muscat and Grech (2023) identified that not all educators were aware of the home language practices and language choices; therefore, some made instructional decisions without a holistic understanding of students’ linguistic backgrounds. Similarly, Grande González et al. (2025) highlighted the role of school psychologists, who reported inconsistencies in how multilingual learners were assessed and supported through multi-tiered systems, often due to the use of monolingual assessment tools and unclear protocols. Moreover, many educators expressed limited confidence in applying differentiated and linguistically responsive instruction for multilingual learners with disabilities, citing insufficient training or professional development in bilingual special education. These findings align with previous critiques of professional practices established in monolingual beliefs and mainstream settings. The findings emphasize the importance of systematically including second-language learning and special education services, along with creating clear policies for dual-language support within inclusive settings. Findings indicated that difficulties in bilingual literacy mostly arise from systemic and professional barriers, not from bilingualism or natural learner limitations, supporting the stance against language-restrictive approaches in special education.
In the studies by Frates et al. (2022, 2024), educators discussed the communication needs of students to enhance phonological instruction by aligning them with students’ home language patterns, an essential strategy for learners with extensive support needs. This cross-professional collaboration reinforces the necessity of shared expertise in delivering meaningful, linguistically inclusive instruction and also capitalizes on better time management when working together toward a common goal.
In contrast to these systemic limitations, several intervention-based studies provided compelling evidence that bilingualism is not a barrier but a bridge to literacy for learners with ID. Studies involving children with DS and other neurodevelopmental disabilities (e.g., Forney-Misuraca, 2020; Martin et al., 2021; Muscat & Grech, in press; Ward & Sanoudaki, 2021) demonstrated that learners were capable of acquiring and applying literacy skills in two languages, with cross-linguistic transfer effects particularly evident in phonological awareness and decoding tasks. Forney-Misuraca (2020) reported measurable gains in phonological awareness, a foundational skill for decoding across languages, through a Lively Letters intervention with K–5 students with ID. Ward and Sanoudaki (2021) further demonstrated that bilingual Welsh-English children with DS and ASD exhibited strengths in phonological awareness that supported literacy development across their two languages. Muscat and Grech (in press) found that Maltese phonological awareness significantly predicted English nonword reading performance. Similarly, Martin et al. (2021) highlighted a student with DS in a French immersion program who showed evidence of cross-linguistic learning. These results challenge persistent deficit narratives and align with a growing body of research emphasizing bilingualism’s cognitive and communicative benefits, even for individuals with significant support needs.
Some studies employed structured, multicomponent literacy interventions established in evidence-based practices such as shared reading, phonics instruction, vocabulary development, and visual support strategies. Forney-Misuraca (2020) reported significant gains in phonological awareness and letter-sound correspondence. These findings highlight the potential of systematic phonics instruction for supporting literacy in learners with extensive support needs. Importantly, these findings extend theories of cross-linguistic transfer and interdependence to populations that have historically been excluded from bilingual research, indicating that underlying phonological and decoding processes can support literacy across languages even in the presence of intellectual or developmental disabilities.
Similarly, Frates et al. (2022, 2024) reported that systematic instruction, task analysis, and the use of least-to-most prompting have resulted in measurable improvements in decoding, vocabulary, and phonemic awareness. In the 2022 study, two Spanish-English bilinguals received individualized shared reading sessions that incorporated sight word identification, picture-word matching, and comprehension questions. The instruction emphasized receptive identification of sight vocabulary using visual aids, dual-language praise in English and Spanish, and scaffolded prompts. The authors reported that both students achieved mastery of targeted word sets and maintained performance over time. The 2024 study expanded this model into small-group settings and included three elementary-aged children. In this study, instruction focused on decoding consonant-vowel-consonant (CVC) words using phonics, phonemic segmentation through Elkonin boxes, vocabulary matching, and comprehension questioning. Results demonstrated that the intervention method had a positive impact on students’ ability to decode CVC words. Additional improvements were observed in phonemic awareness and vocabulary knowledge on pre- and post-intervention assessments. Furthermore, high social validity ratings from both parents and supporting professionals indicated that the intervention was not only effective but also acceptable and meaningful in real-world classroom contexts. Beyond demonstrating effectiveness, these studies indicated that evidence-based literacy practices commonly used in monolingual contexts can be meaningfully adapted for bilingual learners, provided that linguistic responsiveness is embedded within instructional design.
Technological and visual innovations were also featured across studies. Larsson et al. (2025) investigated the use of Blissymbolics paired with traditional orthographic print in a South African school for students with diverse home languages. Blissymbols are a standardized system of graphic symbols used in augmentative and alternative communication to support meaning-making and access to language and literacy (McNaughton & Light, 2013). Learners and educators reported improved reading comprehension and vocabulary acquisition, as the semantic clarity of Bliss aided concept explanation across linguistic backgrounds. Educators observed that linguistic knowledge acquired through Bliss often transferred to broader classroom activities, suggesting that Bliss could serve as a cognitive and linguistic bridge to conventional literacy. Conceptually, these findings support multimodal models of literacy development, in which meaning-making is not confined to alphabetic print but distributed across symbolic, visual, and linguistic systems, an approach particularly relevant for learners with complex communication profiles.
Cersosimo (2023) explored the combination of multilingual digital storytelling and virtual reality in a pilot study involving eight children aged 8 to 11 years, including two with mild ID. Pre- and post-intervention questionnaires revealed increased self-efficacy, interest in language learning, and classroom engagement. The ability to co-construct multilingual narratives in a virtual environment promoted identity expression and cross-linguistic awareness.
Inclusive bilingual immersion settings were another area of promising practice. Martin et al. (2021) and Regalla et al. (2024) documented cases where learners with ID participated in French immersion programs with the support of targeted scaffolding, peer interaction, and explicit language instruction. These case studies provide concrete evidence that, when thoughtfully implemented, dual-language programs can foster both linguistic inclusion and academic growth for neurodiverse learners, challenging the assumption that such learners are best served through monolingual or segregated models. These examples contribute to broader inclusion debates by demonstrating that bilingual immersion is not inherently exclusionary for learners with ID, provided that instructional scaffolding and language supports are intentionally designed.
Recommendations for Policy and Practice
The findings from this review offer important recommendations for policy and practice aligned with inclusive education principles. Education systems must ensure that multilingual learners with ID have equitable opportunities to learn to read and write within inclusive, mainstream education settings rather than segregated programs. These approaches should encourage full participation and access for all learners (Larsson et al., 2025; Li, 2022; Shand, 2024).
Educators should adopt instructional strategies that respect and incorporate students’ languages, cultural identities, and communication methods, positioning these strengths as valuable resources rather than deficiencies. This includes the use of translanguaging, or the purposeful use of multiple languages within instruction to support comprehension and learning (Creese & Blackledge, 2010), visual supports (Frates et al., 2022; Regalla et al., 2024), technology-enhanced interventions (Cersosimo, 2023), and narrative-based teaching methods (Gilhuber, 2023; Washburn et al., 2023) that develop engagement and understanding.
Schools should also eliminate English-only policies and reduce their reliance on monolingual assessments, replacing them with bilingual and culturally sensitive measures. This recommendation is supported by findings that English-only instruction and monolingual assessments limit equitable access to literacy and marginalize home languages (Grande González et al., 2025; Muscat & Grech, 2023). Policy frameworks should clearly recognize linguistic diversity as a right, not a barrier, and promote bilingual instruction as a vital element of inclusive education (Muscat & Grech, 2026; Ward & Sanoudaki, 2021).
Effective literacy instruction should be collaborative and interdisciplinary—involving mainstream educators, special educators, bilingual specialists, and other supporting professionals. This need for coordinated planning was highlighted in studies exploring teacher agency and multi-tiered systems of support (Grande González et al., 2025; Li, 2022). This strategy guarantees that both bilingual development and personalized learning needs are met through shared responsibility.
Family engagement is equally vital. Studies on home literacy practices underscore the importance of parents as active partners (Gilhuber, 2023; Muscat & Grech, 2024; Washburn et al., 2023; Yang, 2023). Families should be recognized as co-educators and decision-makers in literacy planning, with their home languages and literacy practices valued as integral to student success. Schools and policymakers must establish structures for authentic family partnerships rather than merely symbolic involvement.
Finally, educators, related service professionals, and family members need ongoing, equity-focused professional development centered on evidence-based literacy teaching, bilingual pedagogies, universal design for learning, and culturally responsive assessment. This recommendation is supported by findings that educators frequently report limited training in bilingual and inclusive literacy practices (Muscat & Grech, 2023; Shand, 2024). Policies should mandate and fund these training programs to support systemic change and ensure that inclusive practices are integrated at all levels.
Future Research Directions
Future research should focus on broadening age representation, especially through studies on literacy development in secondary education and beyond. Longitudinal designs are necessary to follow literacy progress across different developmental stages, considering the lifelong benefits of reading instruction for individuals with intellectual and developmental disabilities. Furthermore, research should incorporate intersectional frameworks to explore how socio-economic status, gender, immigration history, and co-occurring disabilities interact with language learning and literacy outcomes. Studies using culturally and linguistically responsive methods, including assessments normed for multilingual populations, are essential for reducing bias and capturing learners’ full abilities.
Limitations
Some limitations of this review need to be outlined. Many of the studies identified were small in scale and relied on single-case or quasi-experimental designs, lacking long-term data. Furthermore, a key equity concern emerging from a recent review (Leung & Molnar, 2025) is the ongoing reliance on monolingually normed assessments, which may misrepresent the abilities of multilingual learners. Across the reviewed studies, reporting of assessment practices varied considerably. Where assessment tools were specified, several studies relied on measures normed on monolingual populations or acknowledged the absence of bilingual or locally standardized norms. Other studies employed task-based or qualitative approaches that did not involve norm-referenced assessment.
Another limitation relates to the age distribution of participants. Although inclusion criteria spanned ages 3 to 20, the majority of intervention-based studies concentrated on early and elementary education, with minimal research targeting older adolescents in secondary settings. Given that individuals with ID benefit from literacy instruction across their lifespan, this underrepresentation highlights a critical gap. Furthermore, intersectional influences, including socio-economic status, immigration history, other disabilities, or linguistic identity, were rarely investigated, despite their significant potential to shape literacy outcomes and access (Kangas et al., 2023).
Additional limitations relate to the scope and methodology of this scoping review itself. First, while the review aimed for an international perspective, only studies published in English were included, potentially excluding relevant research from non-English-speaking contexts. Second, not all included studies were peer-reviewed; several were doctoral dissertations and one was a conference proceeding, which, while valuable, may not have undergone the same level of peer-reviewing as journal publications. These factors should be considered when interpreting the breadth and generalizability of the findings.
Conclusion
This review emphasized the potential for change in linguistically and culturally responsive literacy instruction for bi/multilingual learners with ID, yet also identified the need for further research, as the area remains relatively unexplored. The review challenged long-standing misconceptions about bilingualism in these populations while highlighting innovative research practices. Nevertheless, persistent barriers still prevail; therefore, further research and resources to support equitable and evidence-based practices are crucial.
Footnotes
Ethical Considerations
This research did not need ethical clearance.
Funding
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research has been funded by the REACH HIGH II Scholars Agreement. Reference number: MEYR 408/2024/3.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
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