When a child uses two or more languages, those languages can influence one another. This is called cross-linguistic influence or transfer. It can appear in speech sounds, vocabulary, grammar, and storytelling. Understanding that interaction helps us recognize what a child knows, identify when support is needed, and choose meaningful therapy goals. [1, 2]
What can influence look like?
| Area | Possible observation | Helpful question |
|---|---|---|
| Speech sounds | A child uses a sound or syllable pattern from one language while speaking another. | Is the pattern expected given the child's languages, dialects, and opportunities to practice each sound? |
| Vocabulary | A child knows a concept in one language but does not yet have the word in the other. | What does the child understand and express across both languages? |
| Grammar | Sentence patterns from a familiar language appear while the child learns an additional language. | Does this reflect language learning, a dialect rule, or a difficulty that extends beyond those patterns? |
| Conversation | A child changes languages with different people or within a conversation. | How does the child use all available language to convey meaning? |
These examples are starting points, not rules that apply to every language pair or a substitute for an evaluation. Languages have different sound inventories, word structures, and sentence patterns. Code-switching is also a typical practice for many multilingual speakers and is not, by itself, evidence of a disorder. [1, 2]
Why one-language testing misses part of the picture
A child's languages may serve different purposes. They might discuss school science in English, tell family stories in Spanish, and understand familiar directions in both. Language experience changes over time and across people and settings; equal skill in every language is not a requirement for multilingual development. [1, 2]
Research with Spanish-English bilingual children found that considering semantic skills in both languages helped classify language impairment more accurately than relying on one language alone. Vocabulary knowledge can be distributed across languages, but even a combined vocabulary score is only one piece of an evaluation. [3] A separate study found that performance in a single language varied with exposure, reinforcing the need to interpret scores in light of a child's language history. [4]
Questions for a thoughtful assessment
Which languages and dialects does the child use? Ask families about when each language was introduced, who uses it with the child, and where it is heard and spoken. A child's strongest language may vary by topic and setting. [1, 2]
Are the observed patterns expected in those languages? A clinician should examine the child's actual languages and dialects before labeling a sound or grammar pattern an error. The same English production can have different explanations depending on the child's language background. [1, 2]
How does the child communicate in each language? Family interviews, observations, and speech and language samples help describe strengths and needs. ASHA recommends sampling the languages the person uses, with interpreter collaboration when needed, while recognizing that scores and structures cannot always be compared directly across languages. [1]
How does the child learn with support? Teaching a new skill and checking what changes can add information about learning. The clinician should combine that information with history, observation, appropriate measures, and family input rather than relying on one task. [1, 5]
What does this mean for therapy?
When a disorder is present, goals should reflect the child's communication needs and the languages that matter in daily life. A clinician might identify skills shared across languages, coordinate with families and interpreters, and monitor growth in more than one language. Improvement may carry from one language to another, but the amount varies. In a small study of two Spanish-English bilingual children with speech sound disorders, treatment of shared sounds in Spanish was followed by gains in English; the authors called for replication with more children. This is promising evidence, not a guarantee for every child or target. [1, 6]
Families can continue to use the language in which they connect most naturally. Share words, stories, songs, and routines in the languages that are meaningful to your child. Tell the SLP what communication looks like outside school so therapy can support participation at home and in the community. [1]
Our approach at Culturally Speaking SLPs
We see multilingual communication as a whole system shaped by a child's relationships and experiences. Looking across languages helps us value what the child already knows and make better decisions about assessment and support.
This article is educational. A specific child's speech and language needs require an individualized evaluation.
References and further reading
1. American Speech-Language-Hearing Association (ASHA). (n.d.). Multilingual service delivery in audiology and speech-language pathology. Practice Portal.
2. McLeod, S., Verdon, S., & International Expert Panel on Multilingual Children's Speech. (2017). Tutorial: Speech assessment for multilingual children who do not speak the same language(s) as the speech-language pathologist. American Journal of Speech-Language Pathology.
3. Peña, E. D., Bedore, L. M., & Kester, E. S. (2016). Assessment of language impairment in bilingual children using semantic tasks: Two languages classify better than one. International Journal of Language & Communication Disorders.
4. Peña, E. D., Bedore, L. M., & Granados Vargas, A. (2023). Exploring assumptions of the bilingual delay in children with and without developmental language disorder. Journal of Speech, Language, and Hearing Research.
5. ASHA. (n.d.). Assessment tools, techniques, and data sources. Practice Portal.
6. Irizarry-Pérez, C. D., Peña, E. D., Bedore, L. M., & Falcomata, T. S. (2024). A cross-linguistic approach to treating speech sound disorders in bilingual children. Clinical Linguistics & Phonetics, 38(5), 433–452.