Which language should you speak to your child? Usually the one you speak best
Speak the language you're fluent, funny and comfortable in, and let your child get the other languages from other fluent people. That's the plain reading of the research, and it runs against advice many parents who moved countries still hear from teachers, doctors and relatives.
The worry behind the advice is understandable. You want your child ready for school in the local language, and you might be the only person they spend all weekend with. But the evidence says the local language arrives through daycare, school, friends and siblings, while the richness of your talk depends a lot on which language you're using.
What changes when a parent speaks a weaker language
The clearest test recorded 60 mothers playing with their 2½ year olds in English. Some were native English speakers, and some were native Spanish speakers who had learned English after age 15. Mothers who rated their English as limited talked just as much as the native speakers, which surprises people, but their talk was thinner: sentences averaged about 2.4 words against 3.4, and they used about 180 different words in a play session against about 300 (Hoff, Core and Shanks, 2019). Mothers who rated their English as good were statistically indistinguishable from native speakers on every measure.
Varied words and longer sentences are exactly what feeds a toddler's vocabulary and grammar, so the cost of switching to a weak language is simpler talk, even when there's just as much of it.
Fluent matters more than native
A study of 50 preschoolers learning Dutch alongside another language found that neither the share of Dutch they heard from native speakers nor having a native Dutch parent predicted their Dutch, while the fluency of the non-native Dutch speakers around them did (Unsworth and colleagues, 2019). The authors' practical suggestion was that a parent who doesn't speak Dutch well might do better speaking the language they know well, while making sure the child hears Dutch from more fluent speakers.
The findings don't line up perfectly across studies. In a Florida study of 29 two-year-olds, the share of English from native speakers did go with bigger English vocabularies (Place and Hoff, 2011). A recent review weighs this and lands where most families can live: very limited proficiency can thin out what a child hears, but intermediate speakers shouldn't automatically avoid a language with their child (Byers-Heinlein, Kircher and Lew-Williams, 2025). If you can play, joke and comfort in a language, it counts.
The local language will find your child
Clinicians are advised not to discourage parents from speaking their native language to their children, because late-learned input may support the new language less than fluent input does, and dropping the home language takes away the child's chance to learn it at all (Hoff and Core, 2015). Reviews of the field back this up from several angles. More home-language exposure wasn't found to hold back children's majority language in a review of 42 studies (Hollebeke and colleagues, 2020). Reading picture books at home in the home language helped preschoolers learn English words as well as reading in English did (Roberts, 2008).
Siblings carry the local language home, too. In a study of 113 children learning English after migrating, more English from older siblings went with stronger English, while more English from mothers didn't, and mothers' fluency in English also mattered (Sorenson Duncan and Paradis, 2020). A review of heritage-language research sums up the practical upshot: parents don't need to switch to a language they speak less well to help their child learn it (Paradis, 2023).
Bring in more voices
The one thing a single parent can't provide is variety of speakers, and it seems to matter. In the Florida study, toddlers who heard English from more different people had bigger English vocabularies and more complex grammar, even after counting how much English they heard (Place and Hoff, 2011). For the home language that means grandparents on video, a babysitter, a weekly playgroup, the shopkeeper who's from the same town as you. For the local language it means daycare, neighbors and the playground, which tend to show up whether you plan them or not.
What if you're learning the local language yourself?
Use it with your child when it's fun and natural, in songs, games and moments with local friends, and keep your strongest language as the one you live in together. A language app or game can add a few words in a language nobody at home speaks well, and we build one, but it can't tell a bedtime story the way you can in your own words.
Questions parents ask
Should I speak the local language to my child to help them at school?
If it's a language you learned late and speak less well, research suggests speaking your strongest language instead. Children of parents with limited proficiency hear shorter sentences and fewer different words, and the local language reliably arrives through daycare, school and friends.
Does it matter if I'm not a native speaker?
Fluency matters more than native status. A Dutch study found the fluency of non-native speakers, rather than whether a parent was native, predicted children's Dutch. If you can play, joke and comfort in a language, it's a good language to use.
Will speaking my home language hurt my child's school language?
A review of 42 studies found no case where more home-language exposure held back the majority language, and reading at home in the home language helped preschoolers learn English words as well as reading in English.
Sources
- The quality of child-directed speech depends on the speaker's language proficiency, Erika Hoff, Cynthia Core and Katherine Shanks, Journal of Child Language, 2019
- Predicting bilingual preschoolers' patterns of language development: degree of non-native input matters, Sharon Unsworth, Susanne Brouwer, Elise de Bree and Josje Verhagen, Applied Psycholinguistics, 2019
- A systems framework of bilingual language acquisition, Krista Byers-Heinlein, Ruth Kircher and Casey Lew-Williams, Annual Review of Developmental Psychology, 2025
- Properties of dual language exposure that influence two-year-olds' bilingual proficiency, Silvia Place and Erika Hoff, Child Development, 2011
- What clinicians need to know about bilingual development, Erika Hoff and Cynthia Core, Seminars in Speech and Language, 2015
- Sources of individual differences in the dual language development of heritage bilinguals, Johanne Paradis, Journal of Child Language, 2023
- Home language environment and children's second language acquisition: the special status of input from older siblings, Tamara Sorenson Duncan and Johanne Paradis, Journal of Child Language, 2020
- Home storybook reading in primary or second language with preschool children, Theresa Roberts, Reading Research Quarterly, 2008
- Can family language policy predict linguistic, socio-emotional and cognitive child and family outcomes? A systematic review, Ily Hollebeke, Esli Struys and Orhan Agirdag, Journal of Multilingual and Multicultural Development, 2020
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