By Sarah Holman
Dyslexia is the most common learning disability, affecting an estimated 20% of the population. Distinguishing reading and spelling difficulties caused by dyslexia from challenges that stem from learning a second language can be difficult. Accurate diagnosis depends on understanding the orthographic complexity of the languages involved and how those features affect reading, spelling and overall literacy development.
Language-specific features often influence how a learner reads and spells. For that reason, diagnosticians evaluating emergent bilingual students must be well versed in second language acquisition, cross-linguistic assessment, and culturally responsive interpretation of test results. Expertise in areas such as language dominance, native language attrition, cross-linguistic transfer, and the role of special language programs and sociocultural factors is critical for accurate identification of dyslexia in bilingual populations.
Guidelines for evaluating dyslexia in bilingual students
Based on my experience as a special education coordinator, diagnostician and bilingual teacher, the following practical guidelines can help professionals reach valid conclusions when assessing dyslexia in students who are learning—or use—more than one language.
- Establish language proficiency and dominance first. Before selecting assessment measures, determine which language(s) the student is dominant in and has proficiency in. A comprehensive language profile, backed by formal measures of language ability, should guide which language(s) are used for testing and how results are interpreted.
- Account for language-specific reading processes. Understand how the native language’s orthography and typical reading processes influence learning in a second language. Knowledge of these influences helps determine which patterns are developmentally typical for bilingual learners and which may indicate a learning disability.
- Use peer comparisons thoughtfully. Compare a student’s performance to peers with similar linguistic, educational and cultural experiences rather than to monolingual norms alone. The central question is whether the student’s performance diverges significantly from peers who share comparable language backgrounds and instructional opportunities.
- Differentiate conversational and academic language skills. Recognize that conversational fluency does not equal academic language proficiency. Academic language—vocabulary, complex syntax and abstract discourse—is needed to read textbooks, follow classroom directions and demonstrate comprehension on academic tasks. A student may be socially fluent in a second language while still struggling with the language of instruction.
- Assess reading fluency and language-specific profiles. In some languages, such as Spanish, dyslexia may show differently—word-level decoding may be relatively stronger while fluency, prosody and comprehension are more affected. Evaluate fluency across word, syntactic and passage levels because each component contributes to higher-order reading skills like comprehension.
- Compare within-language skill areas. Create a functional profile within each language by comparing receptive and expressive abilities, listening comprehension and reading in the same language. Then perform cross-language comparisons for the same domains to see whether difficulties are present across languages or isolated to one.
- Consider contextual factors. Take into account a student’s age, home language, primary language used at school and in the community, educational history and socioeconomic background. These factors affect language exposure and academic opportunity and must inform interpretation of assessment outcomes.
The consequences of missed or inaccurate identification
Emergent bilingual students are often underidentified for dyslexia, in part because evaluators may confuse normal stages of second language acquisition with the symptoms of a learning disability. Underidentification delays needed intervention and reduces long-term academic outcomes. For example, publicly available data from Texas illustrates this disparity: emergent bilinguals make up roughly 22% of the student population but account for only around 15% of students identified with dyslexia. Overall dyslexia prevalence in Texas is estimated at about 5%, yet fewer than 1% of emergent bilingual students are identified with dyslexia—suggesting significant underidentification in this group.
Careful, culturally and linguistically informed assessment is essential to avoid both over- and under-referral. Evaluators must distinguish which reading and writing difficulties reflect second language learning and which point to dyslexia so that students receive appropriate instruction and timely interventions.
About the author
Dr. Sarah Holman is a former special education coordinator, diagnostician and bilingual teacher. She currently serves as Director for Riverside Insights. This article was originally published by The Learning Counsel, a research institute and news media hub focused on the shift in education toward digital curriculum.