My child understands our language but answers in English.

The short answer

This is very common. Researchers describe it almost as a rule of thumb: “parents tend to use the minority language,” while “children tend to use the majority language.”¹ In a survey of 1,899 families, every child spoke the majority language, while speaking the minority language was not universal.² Your child understanding you is a real achievement, and on its own, answering in English is not a sign of a delay.³

It is still worth a gentle response, because understanding a language and speaking it grow somewhat separately. English here stands in for whichever language surrounds your family.

Why it happens

Your child has noticed that English works everywhere, and that you understand it. Bilingual children learn to choose the language suited to the person in front of them.³ Answering you in English is usually that same skill at work.

Life around them pushes the same way. In a study of Spanish–English homes, children showed stronger growth in English than in Spanish between 30 and 60 months, and the authors noted that early exposure to Spanish at home does not guarantee a child will acquire it.⁴ Older siblings add to the tide. In two studies of toddlers in bilingual homes, older siblings used English with them more than other household members did. A school-aged sibling also increased mothers’ use of English, and toddlers without one were more advanced in Spanish.⁵

Why speaking still matters

Hearing a language builds understanding. Using it seems to build speaking in its own right. One study followed 47 Spanish–English children from 30 to 42 months, whose choices about which language to speak meant that what they said did not match what they heard. Their speaking was linked to growth in their expressive vocabulary, but not to growth in what they understood.⁶ That study measured English, and it suggests the same logic for any language: a child gets better at saying things by saying them.

What tends to help

• Staying in your language. Replying in it, even to an English answer, keeps it in the conversation. Understanding comes first, and your replies are what it is built from.
• Handing back the phrase. If your child says “I want water,” you can answer with the whole thing in your language as you pour it. ASHA’s advice is to repeat what your child says and add to it.⁷ They do not need to say it back.
• A soft “what did you say?” In one study, two- and three-year-olds played with an adult who used only one language. When the children used the other language, they could switch to match, even after a plain “What?”⁸ That was a game with a researcher, so it shows that children can do this, not that it should happen every time. The odd one, said warmly, is plenty.
• People who need the language. A grandparent on a video call, a caregiver or a playgroup gives your child a real reason to use it, because English will not work there. The number of different speakers a child hears can matter too.⁹
• Places where the language lives. Bedtime songs, a favorite book or the same words at breakfast give it a regular home.

We would not make it a test. A tired three-year-old waiting on the right words is having a hard moment, not a language lesson. Some weeks they will answer in English all week, and you can still answer in yours.

When to ask

Answering in English on its own is not a reason to worry. The AAP and ASHA say a speech or language problem shows up in all the languages a child uses, so the question is about your child’s talking as a whole.³ It is worth talking with your child’s doctor if your child has few words across their languages, has trouble understanding, or has lost skills.¹⁰ An assessment should look at every language your child uses.³ Our late-talker guide walks through what happens next, and our guide to bilingual children and speech delay covers why two languages are not the cause.

Having the words ready

Your own home language may have gaps for toddler talk, especially if you grew up speaking it only at home. Their First Words has 500+ everyday phrases in nine themes and 1,000+ words, in eight languages, with a female and a male native voice on every card. 75 words and 35 phrases are free. It gives you the phrase when you are reaching for it, and the conversation stays yours. If your family is planning who speaks what, our guide to one parent, one language is a good next read.