A bilingual child may know certain words in one language and different words in another. They may speak mostly one language at school and another at home. They may even seem much more confident in one language than the other.
That is why evaluating a bilingual child in only one language can give an incomplete picture of what they actually know and can do.
In most cases, a speech and language evaluation should consider both of your child’s languages, even when one language is clearly stronger. Looking across both languages helps the evaluator distinguish normal differences related to bilingual development from difficulties that could indicate a true speech or language disorder.
Quick Answer
Yes. In most cases, a bilingual child should be evaluated in both languages.
That does not necessarily mean your child will receive identical standardized tests in each language. Instead, the speech-language pathologist (SLP) should gather meaningful information about how your child understands and communicates in both languages.
This may include:
- Language samples
- Parent and caregiver interviews
- Observations
- Dynamic assessment
- Informal or criterion-referenced activities
- Standardized tests when appropriate
- Help from a trained interpreter when the SLP does not speak your child’s home language
The goal is not to determine whether your child’s two languages are equally strong. It is to understand your child’s overall language abilities across both languages.
Key Takeaways
- Both languages matter. A bilingual child’s language abilities may be distributed across two languages rather than contained entirely within one.
- One weak language does not necessarily mean a language disorder. Limited exposure can affect vocabulary, grammar, comprehension, and confidence.
- Difficulties across both languages are generally more concerning. Evaluators look for patterns rather than relying on one low test score.
- The languages do not have to be tested in exactly the same way. Language samples, interviews, observations, and dynamic assessment can provide valuable information when standardized testing is inappropriate or unavailable.
- Parents are an important part of the evaluation. Your knowledge of how your child communicates at home can reveal abilities that may never appear during a testing session.
Why Should a Bilingual Child Be Evaluated in Both Languages?
Bilingual children do not necessarily develop identical skills in each language.
A child might know the names of foods and family members primarily in the language spoken at home while knowing classroom vocabulary primarily in English. Another child might understand the home language very well but prefer answering in English.
These differences can be part of normal bilingual development.
This distribution of language skills is one reason an English-only assessment can be misleading. If the evaluator sees only one part of your child’s language system, important strengths may be missed.
A Child Can Be Stronger in One Language Than the Other
It is normal for bilingual children to have a stronger language, sometimes called a dominant language.
Language dominance can be influenced by:
- How much your child hears each language
- Who speaks each language with your child
- Which language is used at school
- Which language friends and siblings use
- How often your child needs to speak each language
Dominance can also change over time.
A child who primarily speaks Spanish at home, for example, may gradually become stronger in English after starting school.
That shift does not mean the child is losing the ability to be bilingual, nor does having uneven abilities mean something is wrong.
If you want to understand this pattern in more detail, see our guide to language dominance in bilingual toddlers.
One Language May Hide Skills the Other Language Reveals
Imagine a child who has had relatively little exposure to English.
During an English evaluation, the child has trouble naming pictures, following directions, or forming sentences. Those results could look concerning when viewed by themselves.
But suppose the same child communicates effectively in the home language, understands complex directions, tells simple stories, and learns new language concepts easily.
That additional information changes how the English results should be interpreted.
The important question is not simply:
“How well did this child perform in English?”
It is:
“What does this child’s communication look like across both languages?”
That distinction can help prevent normal bilingual differences from being mistaken for a language disorder.
Can Testing Only One Language Lead to Misdiagnosis?
It can.
Many standardized language tests were developed primarily using monolingual children. A bilingual child may therefore perform poorly for reasons that have more to do with language experience than underlying language ability.
Limited exposure to the language of the test can affect:
- Vocabulary
- Sentence structure
- Comprehension
- Word retrieval
- Familiarity with test instructions
- Comfort responding to an unfamiliar adult
This is particularly important when a child’s weaker language is the only language being tested.
A low score tells the evaluator that the child had difficulty with that particular task under those particular conditions. It does not automatically explain why the child struggled.
Limited Exposure Is Not the Same as a Language Disorder
A child learning English may know fewer English words than a monolingual English-speaking child simply because the bilingual child has had fewer opportunities to hear and use those words.
That is a language difference related to experience.
A true language disorder is different. It affects a child’s underlying ability to learn, understand, or use language and should not appear only because the child is being tested in a less familiar language.
This distinction is at the heart of language delay vs. bilingual development.
Evaluators therefore look for evidence across languages, situations, and types of communication before deciding that a disorder is present.
What Does an Evaluation in Both Languages Actually Look Like?
Evaluating both languages does not necessarily mean giving your child two identical sets of tests.
In fact, directly translating an English standardized test into another language can make the test results invalid because the translated version may no longer measure exactly what the original test was designed to measure.
Instead, a bilingual evaluation usually combines several sources of information.
A Detailed Language History
The evaluator should ask about your child’s experience with each language.
You may be asked:
- Which languages your child has heard since birth
- When regular exposure to each language began
- Who speaks each language with your child
- Which language your child hears at home
- Which language is used at school or daycare
- Which language your child prefers to speak
- Whether your child’s language use has changed over time
This information gives the evaluator context for interpreting your child’s performance.
A child who has heard English for six months should not necessarily be expected to perform like a monolingual English-speaking child of the same age.
Language Samples
A language sample lets the evaluator examine how your child communicates more naturally.
Depending on your child’s age, the SLP might observe conversation, play, storytelling, picture description, or another activity that encourages spontaneous language.
Samples can reveal vocabulary, grammar, sentence length, storytelling ability, speech patterns, and how effectively your child communicates ideas.
Whenever possible, samples should be collected in both languages.
Because language sampling can provide information that standardized testing misses, we have a separate guide explaining how language samples are used with bilingual children.
Dynamic Assessment
Dynamic assessment looks at how your child learns when given help, rather than measuring only what your child already knows.
An evaluator might introduce an unfamiliar language task, teach the child how to complete it, and then see how well the child applies what was taught.
A child whose difficulty comes primarily from limited experience may improve quickly with appropriate teaching. A child with an underlying language disorder may continue to have difficulty even after receiving support.
Dynamic assessment can therefore be especially useful when standardized norms do not adequately represent a child’s linguistic background.
You can learn more about this process in our guide to dynamic assessment for bilingual children.
Parent and Teacher Information
What your child does outside the testing room matters.
Parents can describe how the child communicates with family members in the home language. Teachers can explain how the child follows directions, participates in conversations, tells stories, and communicates with peers at school.
When similar concerns appear across languages and environments, those patterns can provide important evidence.
What If My Child Uses One Language Much More Than the Other?
Your child should generally still have both languages considered.
Bilingualism does not require equal proficiency.
A child may understand the home language well but rarely speak it. Another may speak both languages but have a much larger vocabulary in the language used at school.
The evaluator should interpret these differences in light of your child’s actual exposure.
For example, weak vocabulary in a language your child hears only a few hours each week would mean something very different from weak vocabulary in a language your child has heard and used extensively since birth.
This is why a detailed language history is so important.
What If the Speech-Language Pathologist Does Not Speak Our Home Language?
This is a common concern, and it does not automatically mean your child can only be evaluated in English.
When the SLP does not speak your child’s home language, the evaluation may involve a trained interpreter.
The interpreter can help the SLP:
- Interview parents or caregivers
- Give instructions
- Collect language samples
- Understand the child’s responses
- Identify culturally or linguistically appropriate language patterns
The SLP remains responsible for selecting appropriate assessment methods and interpreting the results.
Language samples, parent interviews, observations, and dynamic assessment become particularly valuable when standardized tests are not available in your child’s language.
What should generally be avoided is simply translating an English standardized test word for word and treating the resulting score as though the translated test had the same norms and validity as the original.
What Patterns Are Evaluators Looking For Across Both Languages?
One of the most important parts of bilingual assessment is determining where difficulties occur.
If a child struggles mainly in a newer or less frequently used language but communicates effectively in the stronger language, limited exposure may help explain the difference.
If similar difficulties appear in both languages, concern about an underlying language disorder becomes greater.
For example, the evaluator may look at whether your child:
- Has difficulty learning new words in both languages
- Struggles to understand directions in both languages
- Has persistent difficulty forming sentences in both languages
- Has trouble telling or retelling a simple story in either language
- Makes unusual language errors that cannot be explained by normal influence from the other language
No single pattern proves that a disorder is present.
Instead, the SLP combines information from multiple sources to determine whether the overall profile looks more like typical bilingual development or an underlying speech or language difficulty.
What Should Parents Ask Before the Evaluation?
You do not need to know the technical details of every test the SLP plans to use. A few practical questions can tell you a great deal about whether your child’s bilingual background will be considered appropriately.
Ask:
- Will both of my child’s languages be considered during the evaluation?
- How will you determine how much exposure my child has had to each language?
- What will you use besides standardized tests?
- Will you collect language samples?
- Will you use dynamic assessment?
- If you do not speak my child’s home language, will you work with an interpreter?
- How will you distinguish limited language exposure from a possible language disorder?
- How will information from parents and teachers be included?
The evaluator should be able to explain not only what will be assessed, but also why those methods are appropriate for your child’s language background.
How Can Parents Help Make the Evaluation More Accurate?
Parents have information the evaluator cannot get from a testing session alone.
Before the evaluation, think about how your child actually uses each language during an ordinary week.
Write Down Your Child’s Language History
Make a simple timeline showing:
- When your child first heard each language
- Who regularly speaks each language
- Where each language is used
- Approximately how much exposure your child gets
- Any major changes in language use
You do not need precise percentages. Reasonable estimates and specific examples are usually more useful than trying to calculate exposure perfectly.
Bring Examples From Both Languages
If appropriate, bring short examples of your child’s natural communication.
These might include a brief recording of your child playing, talking with a grandparent, looking at a book, or participating in another familiar routine.
Natural examples are more useful than asking your child to perform or repeat rehearsed words for the recording.
Describe Concerns in Both Languages
Try to explain not only what worries you, but where and when it happens.
For example:
“My child has trouble following two-step directions in both English and Spanish.”
is more informative than:
“My child doesn’t understand directions.”
Specific examples help the evaluator determine whether a difficulty appears across languages or primarily in one particular environment.
Keep Speaking Your Home Language
There is generally no reason to stop using your home language before an evaluation.
Doing so can actually remove useful information about what your child understands and communicates in the language they know best.
Continue communicating naturally in the language that works best for your family.
What Happens After Both Languages Are Evaluated?
The SLP brings together the different pieces of evidence rather than making a decision from one test score.
The final interpretation may include:
- Strengths in each language
- Areas of difficulty
- Differences that can reasonably be explained by language exposure
- Patterns that appear across both languages
- How your child responded to teaching or prompting
- Information from parents and teachers
- Whether the difficulties affect everyday communication
- Recommendations for support or further evaluation
The goal is to determine whether your child’s profile is consistent with typical bilingual development or whether there is evidence of a speech or language disorder that requires additional support.
If your child has already completed an assessment, our guide to understanding a bilingual speech evaluation report explains what the results and recommendations may mean.
Final Thoughts
A bilingual child’s communication cannot always be understood by looking at one language in isolation.
Children may have different vocabulary, different strengths, and different levels of confidence in each language because their experiences with those languages are different.
That is normal.
A good bilingual evaluation takes those differences seriously. It considers both languages, your child’s language exposure, information from parents and teachers, natural communication, and how your child responds to appropriate support.
The goal is not to prove that both languages are equally strong.
It is to answer the question that matters most:
Is what we are seeing an expected part of bilingual development, or is there evidence of an underlying speech or language difficulty?
Considering both languages gives the evaluator a much better chance of answering that question accurately.
Frequently Asked Questions
Does my child need to speak both languages equally well to be evaluated in both?
No. Uneven language skills are common in bilingual children. The evaluator should consider how much experience your child has with each language when interpreting strengths and weaknesses.
What if my child understands our home language but mostly answers in English?
That does not mean the home language should be ignored. Understanding is part of language ability, and information about what your child comprehends in the home language can help complete the overall picture.
Can a bilingual child have a real language disorder?
Yes. Bilingual children can have speech and language disorders just as monolingual children can. The challenge is distinguishing a true disorder from differences caused by language exposure and normal bilingual development.
What if no bilingual speech-language pathologist speaks my child’s language?
An SLP can work with a trained interpreter and use parent interviews, language samples, observations, dynamic assessment, and other appropriate methods to gather information about the home language.
Should we stop speaking our home language before the evaluation?
No. Continue using your home language naturally. It gives your child meaningful language exposure and provides the evaluator with important information about your child’s communication abilities.
Can one standardized test determine whether my bilingual child has a language disorder?
No single test should determine the diagnosis. Standardized test results, when appropriate, should be considered alongside language history, samples, observations, parent and teacher information, dynamic assessment, and patterns across both languages.