Bilingual Children and Speech Therapy: What Parents Need to Know

Parents raising children in bilingual households frequently encounter questions and concerns about language development — and sometimes receive conflicting advice. Should they speak only one language at home? Will two languages confuse the child? If the child is a late talker, is bilingualism the cause? And if speech therapy is needed, how does it account for two languages?

Here is what the research shows and what parents of bilingual children need to know.

Bilingualism Does Not Cause Language Disorders

One of the most persistent myths about bilingual children is that exposure to two languages causes or contributes to language delays and disorders. This is not supported by research. Bilingualism does not cause language disorders. A bilingual child who has a language disorder has it because of the same factors that cause language disorders in monolingual children — not because they are learning two languages.

The flip side is equally important: bilingualism does not protect against language disorders either. A bilingual child can have a language disorder, and when one is present it affects both languages.

Normal Bilingual Language Development

Bilingual language development follows its own normal pattern that can look different from monolingual development in ways that are sometimes mistaken for delays or disorders:

Mixing languages. Bilingual children mix words from both languages within the same utterance — a phenomenon called code-switching or code-mixing. This is a normal feature of bilingual communication, not a sign of confusion or disorder.

Different vocabulary in different languages. Bilingual children often have words in one language that they do not have in the other. A child who speaks Spanish at home and English at school may know words for kitchen objects in Spanish but words for school materials in English. When vocabulary is assessed in only one language, the child may appear to have a smaller vocabulary than they actually do — because their total conceptual vocabulary spans both languages.

Slightly different developmental timing. Some aspects of bilingual language development may occur at slightly different points than in monolingual children, but bilingual children achieve the same developmental milestones within the typical range.

When Is a Bilingual Child's Language Difference a Disorder?

Assessing whether a bilingual child has a language disorder requires looking at performance across both languages. A language disorder in a bilingual child is present in both languages — not just one. If a child is struggling in one language but performing typically in the other, the difficulty likely reflects a language difference (less exposure, less practice) rather than a language disorder.

This distinction requires careful, skilled assessment that accounts for the child's language history, the degree of exposure to each language, and their performance in both languages. A speech-language pathologist who evaluates bilingual children should have training and experience in bilingual assessment.

Evaluating a Bilingual Child

Assessing language in bilingual children is more complex than assessing monolingual children, and many standardized language tests are normed on monolingual English-speaking children — making them inappropriate for bilingual children if used without interpretation.

A thorough evaluation of a bilingual child should include:

• A detailed language history (which languages are spoken at home, by whom, how frequently, and since when)
• Assessment in both languages whenever possible
• Use of dynamic assessment approaches that measure the child's ability to learn rather than simply current knowledge
• Collaboration with a speech-language pathologist who is fluent in the child's other language, or use of a trained interpreter with clear protocols

If a monolingual English-speaking SLP is the only option available, they should have specific training in bilingual assessment and should partner with an interpreter using established protocols — not simply translate tests, which produces inaccurate results.

Should Parents Stop Speaking Their Home Language?

This is perhaps the most common and most consequential piece of advice parents receive — and it is wrong. Research consistently shows that parents should continue speaking to their children in the language they know and use most naturally.

The language in which a parent communicates most naturally, most richly, and with the most emotional connection is the language in which they provide the richest language input. Asking a parent to switch to a language they are less comfortable in to avoid "confusing" the child typically results in the child receiving lower-quality language input — not more of it.

If a child with a language disorder needs speech therapy, the therapy should be delivered in both languages, or at minimum in the home language as well as English. Maintaining the home language supports family connection, cultural identity, and cognitive development.

Finding the Right Speech-Language Pathologist

For bilingual children, finding a clinician with specific experience in bilingual language development and assessment is important. Ask directly:

• Do you have experience assessing and treating bilingual children?
• How do you assess language in both languages when one may not be English?
• Do you work with interpreters, and if so, what is your protocol?
• How do you distinguish bilingual language differences from language disorders?

ASHA maintains resources on bilingual service delivery and can help connect families with appropriately trained clinicians.