In some ways. A study of 669,498 English speakers found grammar-learning ability stays high until about 17 and then declines, and late starters rarely lose their accent. But adults make faster progress at first, and in classroom studies older beginners outpaced younger ones after the same hours of teaching. How much input you get matters as much as age.
Is there a critical period for learning languages?
The idea goes back to Eric Lenneberg, who argued in 1967 that a first language not learned by puberty can't be learned normally. For second languages, proposed cut-off ages have ranged from 2 to 13.
The largest test so far is Hartshorne, Tenenbaum and Pinker's 2018 study, which gave an online English grammar quiz to 669,498 native and non-native speakers. Their model put the age at which grammar-learning ability starts to decline at 17.4, much later than earlier estimates. To reach native-like grammar, though, learners had to start by about 10–12, because those who start later "run out of time" before the decline sets in.
| What the study found | What it didn't test |
|---|---|
| Learning rate for grammar stays high until about 17, then declines steadily | Vocabulary or pronunciation, which the authors say may follow a different pattern |
| Native-like grammar needs a start by about 10–12 | Languages other than English, or spoken skills; it was a written quiz |
| The authors call it a sharply defined critical period, but one that ends much later than once thought | Why it happens: the authors list social, linguistic and neural possibilities without testing them |
So an adult is unlikely to become indistinguishable from a native speaker. That's a different question from whether an adult can learn a language well, and on that the evidence is far more encouraging.
What advantages do adults have?
Speed, at least at the start. Reviewing the research, Carmen Muñoz notes that studies in naturalistic settings, such as immigrants learning the local language, consistently show older learners progressing faster at first and younger learners ending up higher in the long run. Krashen, Long and Scarcella described this pattern in 1979, and Krashen argues that adults pick up grammar rules such as word order and word endings faster than children.
In classrooms, age can even work the other way. Muñoz reports that in foreign-language teaching, early starters don't outperform late starters when the amount of instruction is the same, even after many years, and that older school pupils outperform younger ones after the same number of hours. Her explanation is that older learners are better at explicit learning, while young children need massive exposure to use their talent for implicit learning, and a few lessons a week don't provide it.
| Younger starters | Adult starters | |
|---|---|---|
| Early progress | Slower | Faster |
| Long-term ceiling with lots of exposure | Higher, often native-like | Usually below native, especially in accent |
| Learning from rules and explanations | Weaker | Stronger |
| Learning from a few lessons a week | No advantage | Often ahead after the same hours |
| Reading, choosing material, planning | Limited | A real advantage |
What stays hard for adults?
Accent is the clearest case. Adult learners nearly always keep a recognisable foreign accent, even some whose grammar is perfect, although studies have found late learners who sound native when reading aloud. Fine grammatical detail is the other: Hartshorne's data suggest that adults who start late rarely reach native-level scores, however long they keep going.
Adults also tend to get less input than children do. A child surrounded by a language hears it for most of their waking hours; an adult learner fits it around work and family. Muñoz's research on foreign-language learners finds that measures of input, such as hours of instruction, time abroad and how often learners use the language, are significantly associated with proficiency. Much of the gap between children and adults may come down to that.
How should adults learn?
- Use explicit knowledge. Adults learn rules fast, so a short explanation of a grammar point you keep meeting is time well spent.
- Then get a lot of input. Rules don't replace hearing and reading a language in volume. Reading lets you get that volume at your own pace; see immersion at home.
- Read things written for adults. Children's books are easy, but they aren't written for your interests.
- Speak, even with an accent. Being understood is the goal. Our page on input vs output looks at when speaking practice pays off.
Contos writes even its beginner stories about adult lives. In the Contos library (October 2026), the 192 A1 series across 16 languages include 107 tagged comedy, 73 mystery, 69 romance and 55 family (most carry two genres). This is what A1 French looks like:
Sophie est architecte à Lyon. Elle travaille beaucoup. Elle aime son métier. Mais elle n'a pas de petit ami.
Read chapter 1 of an A1 series and see how much of an adult story you can already follow.
Read free in your browserFrequently asked questions
Is it too late to learn a language at 40, 50 or 60?
No. The research on age is mostly about reaching native-like levels, especially in accent and fine grammar. Adults can and do reach high levels of fluency, and they often progress faster than children at the start.
Will I ever lose my accent?
Probably not completely. Adult learners nearly always keep a recognisable accent, though a few studies have found late learners who sounded native when reading aloud. A clear accent is no barrier to being understood.
Do children learn languages faster than adults?
Not at first. Older learners usually progress faster early on, and in classrooms they often stay ahead after the same hours of teaching. Children's advantage shows in the long run, with plenty of exposure.
Why does learning feel slower as an adult?
Usually because of time and input, not ability. Adults fit a language around work and family, while children can spend most of the day in it. More regular input closes much of that gap.