Languages

Our household runs on more than one language, which means we have had every version of the same conversation. Will it slow him down. Will he mix them up. Should we pick one and be consistent.

Here is what the research says, stripped of the anxiety.

Mixing is not confusion

Young multilingual children put words from two languages into one sentence. It looks like a system failure. It is not. Adult bilinguals do it too, deliberately, and linguists call it code-switching. Children do it mostly when they lack a word in one language and have it in the other — which is efficient, not confused. It follows grammatical rules, and it fades as vocabulary fills in.

Count the total, not the halves

A three-year-old with two languages may know fewer words in each language than a monolingual peer. Counted together, the total vocabulary is typically comparable. The gap in each individual language usually closes over the school years, and most reliably in the language the child is schooled in.

First words, first sentences and the general shape of language development arrive on roughly the same schedule as for monolingual children. Multilingualism does not cause a language delay. If you suspect a delay, it needs looking at on its own terms — do not let anyone attribute it to the second language and wait.

Understanding runs ahead of speaking

Children almost always comprehend a language long before they will produce it. A child who answers in Dutch when addressed in Bulgarian is not rejecting the language; they are choosing the path of least resistance. Keep speaking it. The receptive vocabulary is being built even when nothing comes back.

What actually determines whether a language sticks

Not the method. The input.

• Quantity. Rough estimates put the threshold at somewhere around a quarter to a third of a child's waking language exposure for a language to develop actively. Below that, it tends to stay receptive.
• Variety of speakers. A language spoken by one parent only is fragile. A language with grandparents, cousins, a playgroup, other children behind it is not.
• A reason to use it. People the child needs the language for. Video calls with a grandmother who genuinely does not speak the other language are worth more than an hour of flashcards.
• Reading aloud. Books carry vocabulary and sentence structures that never come up in "put your shoes on".

One-parent-one-language is a popular strategy and a perfectly good one, but it is not magic and it does not have to be observed to the letter. Language-by-context — this one at home, that one outside — works just as well. What fails is a language with no consistent source.

The part nobody mentions

There will be a stage, usually when school starts, when the community language takes over and your child answers you in it. This is the point where most home languages are lost, and it is lost quietly, by accommodation. You reply in the school language once, then always.

The counter-move is unglamorous: keep going. Do not correct, do not make it a test, do not make speaking your language the price of being understood. Just keep offering it, in books, in food, in people, in trips. A language kept alive at home is a door left open. What the child does with it later is theirs.