Is my bilingual child losing a language? What the research actually says

Add a minority language book to your bedtime or other routine, so it's easy to add an extra serving!

If your bilingual toddler seems to have shifted toward one language over the other lately, perhaps more English at home than usual, or a heritage language that suddenly seems to be deprioritised, you're not imagining it, and it's probably not a "silent period"either.

Here's what's actually going on, and what the research says about supporting the language that is being used less.

Silent period, or something else?

The "silent period" is a real, specific term coined by researcher Patton Tabors: a child suddenly placed in an entirely new language environment, most often between ages three and eight, goes quiet in that new language, sometimes for weeks, sometimes for a few months, before speech emerges. It's a well-documented, harmless stage.

But if your child already speaks both languages and is simply leaning harder into one than the other depending on the day or the week, that's a different phenomenon: a temporary dominance shift, not a silence. This distinction changes what you'd actually do about it.

What the research says about input and dominance

Language dominance in bilingual children tracks closely with the proportion of input they get in each language. Barbara Pearson's foundational 1997 study found that below roughly 20% input in a language, children tend to use it only in a limited, "functionally monolingual" way. A later literature review by Pearson and Lisa Amaral (2014) refined this further: below about 40% input, a language tends to lag behind monolingual peers; above a certain point, additional input stops adding much benefit.

The same review makes a recommendation that's actually quite helpful: roughly 60% minority-language input during the preschool years, not 50%. This isn't about achieving parity across your child's whole week, which is usually impossible once nursery or school come into the picture. It's about weighting the hours your family actually controls, because the majority language gets free reinforcement everywhere else, nursery, school, the playground, television, while the minority language's use is generally more limited.

If your child is in childcare part-time

This scenario is extremely common and rarely explained well. If your child spends several days a week in an English-speaking (or majority-language) nursery, those days will supply English input regardless of anything you do. The compensating move isn't to try to match that input at home. It's to make your home days as rich as possible in the minority language, on purpose, so that across the whole week the balance doesn't tip further than it has to.

Expect the language spoken less that week to show up less in your child's mouth that week. This is not a leak in your system and not evidence you're doing something wrong. The input research predicts exactly this.

A gentler, less certain theory

Some parenting and speech-language literature also describes children's language pausing briefly and normally while they focus on mastering something else entirely, a new motor skill, a new social skill, a leap in the majority language, before returning to where they left off. This is worth knowing as a comforting possibility, though it isn't backed by the same weight of rigorous research as the input-proportion findings above.

The distinction worth keeping in mind: this kind of ordinary, temporary dip is different from true regression, a child losing words, gestures, or social responsiveness they'd already been using freely, and not regaining them. That's a different, rarer situation, and one worth raising with a paediatrician or speech and language therapist rather than managing alone.

What can help in practice

• Anchor one object to the minority language. A specific book, kept permanently in the bedtime pile rather than rotated in occasionally, becomes a ritual rather than a lesson.

• Let every willing adult participate, regardless of fluency. A parent with minimal proficiency reading badly-accented bedtime stories, or repeating words in the minority language still adds a channel of exposure.

• Build in passive, ambient exposure. Radio, background music, songs in the car.

• Let your child "teach" the language if they want to. It flips the usual power dynamic and builds a positive association with the minority language.

• Get the best of the time you have to speak your minority language, don't chase parity across the whole week.

Bottom line

A bilingual toddler's languages don't move in lockstep, and they're not supposed to. Long-term outcomes aren't the result of a perfectly even split, they generally arrive when you make sure the language with less external support gets a deliberately larger share of the hours you do control.

For the longer, more personal essay behind this piece, see the Sowing Tales essay Not a Fifty-Fifty Language Ledger.