Is it too late to start as an adult

What is known

A 2018 study gathered data from almost 670,000 people — orders of magnitude more than anything done in this field before. Its conclusion: the ability to pick up the grammar of a foreign language stays high until about 17.4, after which it starts a steady decline.

Four years later the figure was challenged. A re-analysis of the same data showed that the single point of 17.4 is an artefact of the chosen statistical model: other models give a smooth decline with no threshold at all, and different trajectories for different kinds of learners.

What really changes with age

Worse

Grammar intuition — that very sense of “one does not say it like that” which a native has without rules. An adult compensates with learned rules, and that is noticeably slower.

Pronunciation. Indistinguishability from a native after the teenage years is achieved by very few. Being understandable — by almost everyone, and these are different tasks.

Better

Vocabulary. An adult picks up words faster than a child: they have ready-made concepts for new labels to latch onto, and memorization strategies a child does not have.

Understanding how it works. Being told “this language has no gender” saves an adult weeks, and tells a child nothing.

Purpose. A child learns a language because people around them speak it, and in immersion they get thousands of hours of it. An adult gets minutes of study a day, but decides for themselves what to spend them on and can aim each one at their own gaps.

What actually gets in adults' way

Usually not age but awkwardness. Fear of making mistakes noticeably gets in the way of learning a language — data from almost twenty thousand people in twenty-three countries show it.

And it can be dealt with — the methods have been tested and they work. The simplest thing you can do on your own: practise where nobody can hear you, and don’t compare yourself with others in public.

The second obstacle — expectations. An adult is used to being competent, and in a new language they become, for months, the person who cannot read the signs. That is felt more heavily than the material's difficulty itself, and it passes if you expect it in advance.

What this is based on

Every number above comes from a study, linked next to it. The mark “checked little” means one study stands behind the conclusion — or that researchers still argue about it.

• It is not too late for an adult to learn a language. Grammar comes harder with the years, but there is no age after which the door closes.checked little
  Hartshorne, Tenenbaum & Pinker, 2018, Cognition 177; criticism — van der Slik et al., 2022 · Data on 669,498 people: the ability to pick up grammar stays high until about 17 and then declines. A re-analysis of the same data finds no sharp boundary — the decline comes out gradual.
• Fear of making mistakes gets in the way of learning a language, and noticeably so. The link turns up study after study, and together those studies cover almost twenty thousand people.checked many times
  Teimouri, Goetze & Plonsky, 2019, Studies in Second Language Acquisition 41(2) · 19,933 participants from 23 countries; correlation with results r = −0.36.
• That fear can be dealt with — the methods have been tested and they work.checked many times
  Xiong et al., 2024, Journal of Language and Social Psychology · 37 studies, anxiety reduced by −0.61. Of the seven conditions examined, only age turned out to matter.

Next

• Why a word list doesn't stickWhy rereading a word list barely works, what helps instead, and when to return to a word so it stays. With a walkthrough of the research.
• How many words you need to knowHow many words to learn to understand a conversation, and how many to read without a dictionary. And why “I know almost all the words” does not yet mean “I understood everything”.
• Do streaks and rewards helpWhat is proven about gamification in learning, why rewards for participation undermine motivation, and what is known about streaks — an honest walkthrough with numbers and links.
• How to break down an unfamiliar scriptA practical order for taking on an unfamiliar script: how many characters at a time, why to come back, why you must not start with words, and what to do about look-alike characters.