Will learning English confuse my child or harm our home language?

Does hearing two languages confuse young children?

No. Children all over the world grow up with two or more languages. A review of the research written for parents says that babies who hear two languages "readily distinguish their two languages and show no evidence of confusion" (Byers-Heinlein and Lew-Williams, 2013).

The same review says that mixing words from both languages is normal. If your child does this, our guide My child understands English but won't speak it explains what to say.

Will my child know fewer words in our language?

Maybe fewer in each language at first, but about as many in total.

• Counted together, the words add up. In a study of toddlers about 2 years old, children learning two languages were behind children learning one when each language was tested on its own. But on total vocabulary, counting both languages, the two groups were "comparable" (Hoff and colleagues, 2012).
• Each language follows how much a child hears it. In the same study, a child's scores in each language followed how much of that language they heard.
• The gap is mostly in everyday home words. A study of 1,738 children aged 3 to 10 found that bilingual children understood fewer English words on average. The gap was mostly in words used at home, not words used at school (Bialystok and colleagues, 2010).

The simple lesson: each language grows with how much a child hears it.

These studies are about children who hear two languages a lot, often every day at home. A short English game each day is much less English than that. The research gives no reason to think that this much English harms your home language. Equally, a few minutes a day should not be expected to make your child bilingual.

Should my child master our language before starting English?

There is no need to wait. Learning more than one language does not cause delays, and the research above gives no reason to think short daily English harms the home language. There is also no need to worry about starting later. The review by Byers-Heinlein and Lew-Williams says that earlier is generally better, but also that "it is never too late to learn a new language."

So you don't need to wait, and you haven't missed your chance if you start later. What matters most is that each language gets enough time.

What is the best age to start English?

No birthday closes the door. Three findings help explain why.

• The ability to learn grammar stays strong for a long time. A 2018 study of nearly 670,000 people found that the ability to learn a new language's grammar stays strong until the late teens, about age 17 (Hartshorne, Tenenbaum and Pinker, 2018). It tested grammar only, on a written quiz, and other researchers have questioned the exact shape of the decline (van der Slik and colleagues, 2022).
• In school, older beginners learn faster at first. In Barcelona, students who started English lessons at age 8, 11 or 14, or as adults, were tested after the same numbers of hours of lessons. The older starters learned faster in the early stages (Muñoz, 2006). Later work on classroom learning found that, in the long term and after similar amounts of English, starting age no longer predicted results (Muñoz, 2011).
• An early start helps only if English keeps coming. In Germany, about 3,000 students who started English in Grade 1 were compared with students who started in Grade 3. In Grade 7, the later starters did better in reading and listening. By Grade 9, the early starters did better (Jaekel and colleagues, 2017 and 2022).

Over time, the amount of English a child hears matters more than the age they start. An early start mainly gives more years to build up English, and it helps only if the English keeps coming. This is why an early start helps most for children who live in a language, and much less with a few hours of lessons a week (Muñoz, 2008).

Is one English class a week worth it?

It can be a nice start, but it is not much English. The amount matters: "Quantity of early exposure has a profound effect on children's ongoing language development" (Byers-Heinlein and Lew-Williams, 2013). Short moments on many days may also help more than one long session. In a study with 2-year-olds, the number of different days they heard new words mattered most for saying them (Childers and Tomasello, 2002).

If your child has English once a week at kindergarten, add a few minutes at home on other days. Sing the songs they learned, or ask "Where is the ball?" with words from the class.

How do I keep our home language strong?

• Use it for daily life. Meals, feelings, jokes, stories and family talk.
• Read together in your home language. A review of 38 studies found that young children who can't read yet learn new words from picture books shared with a grown-up, especially when the grown-up asks questions and talks about the pictures (Flack, Field and Horst, 2018). Most of those studies were in children's first language, so they apply directly to reading in your home language.
• Share your own songs and stories. The ones you knew as a child.
• Keep English to short, playful moments. Ten minutes on most days is a good start. Our guide Can I help my child learn English if I don't speak it well? has a simple routine.

When should I ask for help?

ASHA says that a real communication problem "will show up in all the languages they use." So if your child has trouble understanding or speaking in your home language too, not only in English, talk to your child's doctor or a speech-language pathologist. If you are worried, asking is never wrong.

How Kadoo fits

Kadoo is a short English game, not a replacement for your home language. You choose how long each session lasts, from 10 to 30 minutes, and you can add a daily limit, so the rest of the day can stay in your home language. Kadoo's help and parents' area are in eight languages, including French, German, Spanish, Italian and Portuguese (Brazil), while inside the places children hear English. The places open one at a time, from the words children usually learn earliest to the ones they learn later. A few minutes of Kadoo a day will not make your child bilingual, and Kadoo doesn't listen to your child speak: talking together, in both languages, is your part.

Sources

• American Speech-Language-Hearing Association, public information site, Learning More Than One Language.
• Byers-Heinlein and Lew-Williams (2013), Bilingualism in the early years: What the science says, LEARNing Landscapes.
• Hoff, Core, Place, Rumiche, Señor and Parra (2012), Dual language exposure and early bilingual development, Journal of Child Language.
• Bialystok, Luk, Peets and Yang (2010), Receptive vocabulary differences in monolingual and bilingual children, Bilingualism: Language and Cognition.
• Hartshorne, Tenenbaum and Pinker (2018), A critical period for second language acquisition: Evidence from 2/3 million English speakers, Cognition.
• van der Slik, Schepens, Bongaerts and van Hout (2022), Critical period claim revisited: Reanalysis of Hartshorne, Tenenbaum, and Pinker (2018) suggests steady decline and learner-type differences, Language Learning.
• Muñoz, editor (2006), Age and the Rate of Foreign Language Learning, Multilingual Matters.
• Muñoz (2011), Input and long-term effects of starting age in foreign language learning, IRAL.
• Muñoz (2008), Symmetries and asymmetries of age effects in naturalistic and instructed L2 learning, Applied Linguistics.
• Jaekel, Schurig, Florian and Ritter (2017), From early starters to late finishers? A longitudinal study of early foreign language learning in school, Language Learning.
• Jaekel, Schurig, van Ackern and Ritter (2022), The impact of early foreign language learning on language proficiency development from middle to high school, System.
• Childers and Tomasello (2002), Two-year-olds learn novel nouns, verbs, and conventional actions from massed or distributed exposures, Developmental Psychology.
• Flack, Field and Horst (2018), The effects of shared storybook reading on word learning: A meta-analysis, Developmental Psychology.