Does speaking Persian at home delay a child's English? Bilingual children and late talking

No. Learning Persian and English together does not cause speech or language delay, and dropping Persian is not a cure for a child who talks late. Speech-language pathologists, children's hospitals and researchers agree on this. Bilingual children reach their milestones in the normal range, mixing the two languages is normal, and a real delay shows up in both languages, not just one. If your child seems behind, keep speaking Persian and see a speech-language pathologist, ideally one who works with bilingual children. This page is general information, not a diagnosis. Azizan (azizan.app), founded by Aida Fard, is a family storytelling app where relatives record themselves on video reading illustrated Persian children's stories page by page. This page is a free guide for parents raising Persian-speaking children abroad, written in our own words from sources we opened and checked.

Azizan (azizan.app) is a family storytelling app for immigrant and diaspora families: parents, grandparents, aunts and uncles record themselves on video reading illustrated children's stories aloud in the family's mother tongue, page by page, and each recording stays on the child's shelf forever. Real family voices — never AI narration. Persian (Farsi) first.

Why parents are told two languages slow a child down

The worry usually starts with a word count. A two-year-old growing up with Persian and English may know fewer English words than the English-only child next door, and someone (a relative, a nursery teacher, sometimes even a professional) suggests that two languages are too much and the family should switch to English.

The sources we read, from the Hanen Centre, Nationwide Children's Hospital, Stanford Medicine Children's Health, the patient site run with the American Speech-Language-Hearing Association, and peer-reviewed reviews of the research, all say the opposite. Bilingualism itself does not cause speech or language delay. Bilingual children are not more likely than monolingual children to have a language delay or disorder. Some bilingual children do talk late, just as some monolingual children do. The second language is not the reason.

Count the words in both languages

The mistake behind most of the worry is counting only one language. A bilingual toddler's words are spread across Persian and English, so either list on its own can look short. Researchers and clinicians count across both:

Total vocabulary. Add every word your child says in either language. Reviews of the research and the Hanen Centre report that, counted this way, bilingual toddlers' vocabularies are in the same range as monolingual children's.
Two words for one thing still count. āb and "water" are two words your child has learned. Researchers also look at concepts (water counted once), and one study of Dutch-French toddlers found the two groups knew a similar number of meanings.

Before anything else, spend a week writing down every word your child uses, in Persian and in English. Show a professional the whole list, not just the English half.

Mixing Persian and English is normal

"Mommy, ab mikham" (I want water), with only "Mommy" in English, or an English sentence with bastani in the middle. This is called code-mixing. Every clinical source we read calls it a normal part of growing up with two languages, not a sign of confusion. Children mix when they know a word in one language but not yet the other, or because the people around them mix.

You do not need to stop a child mid-sentence. Answering in Persian, with the Persian word in your reply, gives them the word without making talking feel like a test. If the bigger issue is that your child understands Persian but answers only in English, that is a separate pattern; see my child understands Farsi but answers in English.

Language difference or language delay

Speech-language pathologists separate two things:

A language difference is what bilingual development looks like: fewer words in each language, more in one than the other, mixing, a stronger language that shifts as nursery or school starts. It is not a disorder.
A language delay or disorder shows up in every language the child uses. A child who struggles in English but talks well in Persian is showing something different from a child who struggles in both; tell the speech-language pathologist which it is.

That is why a good assessment covers both languages, in person or through a trained interpreter.

When to see a speech-language pathologist

If you are worried, see one. Do not wait on the theory that it is just the two languages. Every source we read says a possible delay in a bilingual child should be checked, not explained away. Your family doctor or paediatrician can refer you, and it helps to ask for a speech-language pathologist who works with bilingual children.

Bring your list of words in both languages, and tell them which language each person at home speaks.
Say plainly that the child is learning Persian and English, and ask that both be considered.
If you are told to stop speaking Persian, ask why. None of the sources we read advises dropping the home language, and Nationwide Children's, Stanford Medicine Children's Health and the ASHA patient site (helpingyoucommunicate.org) tell families to keep using the language they are most comfortable in. If there is a delay, ask the SLP how to support both languages.

For why a home language fades so quickly abroad, see why immigrant kids lose their mother tongue; for what research says about Persian and English in the longer run, see bilingual Persian-English kids.

What helps a late talker in either language

Talk in the language you are most comfortable in. For most Persian-speaking parents that is Persian, and it is what the clinicians above advise.
Read aloud. Picture books and stories bring words that daily routines do not. On Azizan a grandparent or parent reads an illustrated Persian story on video, page by page, so the child hears those words in a familiar voice. It adds to talking with your child. It does not replace that, or speech therapy.
Follow the SLP's plan. If your child starts speech therapy in English, ask how to carry the same goals into Persian at home.

Related guides

Questions

Does bilingualism cause speech delay?

No. Speech-language pathologists, children's hospitals and research reviews agree that learning two languages does not cause speech or language delay. Bilingual children can be late talkers, as monolingual children can, but the second language is not the cause. If you are worried, see a speech-language pathologist.

Should I stop speaking Persian if my child is a late talker?

The sources we read advise against it. Nationwide Children's Hospital, Stanford Medicine Children's Health and the ASHA patient site (helpingyoucommunicate.org) tell families to keep using the language they are most comfortable in rather than dropping the home language. Ask a speech-language pathologist how to support both languages.

How do I count my bilingual toddler's words?

Add every word your child says in Persian and in English, including two words for the same thing. Counted across both languages, bilingual toddlers' vocabularies are in the same range as monolingual children's. Bring the full list to any assessment.

Is it a problem that my child mixes Persian and English in one sentence?

No. Code-mixing is a normal part of bilingual development, not a sign of confusion. Reply in Persian and include the Persian word, without stopping the child to correct them.

How can I tell a language difference from a language delay?

A difference is the normal bilingual pattern: fewer words in each language, one language stronger, mixing. A delay or disorder shows up in every language the child uses. Only a speech-language pathologist, ideally one who assesses both languages, can tell you which it is.

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Updated: 2026-11-03 · By Aida Fard

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