To master a language, start learning it early

To master a language, start learning it early(ˈərlē)

New evidence(ˈevədəns) suggests a drop-off in results after the age of 17

Those who want to learn a foreign(ˈfär-,ˈfôrən) language, or want their children to, often feel they are racing(ˈrāsiNG) against the clock. People seem to get worse at languages as they age. Children often learn their first without any instruction, and can easily become multilingual(ˌməltēˈliNGg(yə)wəl,ˌməltī-) with the right exposure(ikˈspōZHər). But the older people get, the harder it seems to be. Witness(ˈwitnis) the rough(rəf) edges(ej) on the grammar(ˈgramər) of many immigrants(ˈimigrənt) even after many years in their new countries.

Scientists mostly agree that children are better language learners, but do not know why. Some posit(ˈpäzit) biological(ˌbīəˈläjikəl) factors. Is it because young brains(brān) have an extreme(ikˈstrēm) kind of plasticity(plaˈstisitē)? Or, as Steven Pinker, a Harvard psychologist(sīˈkäləjist), argues(ˈärgyo͞o), an instinct for language-learning specifically, which fades as the brain ages and (in evolutionary(ˌevəˈlo͞oSHən) terms) is no longer needed? Others think children have special environments and incentives(inˈsentiv), not more conducive(kənˈd(y)o͞osiv) brains. They have a strong motivation(ˌmōtəˈvāSHən) to communicate with caregivers(ˈke(ə)rˌgivər) and imitate peers(pi(ə)r), and are not afraid(əˈfrād) of making mistakes in the way adults are.

Some believe any “critical(ˈkritikəl) period(ˈpi(ə)rēəd)” may only apply to the sounds of a foreign tongue(təNG). Adults struggle with accents(ˈækˌsɛnt): eight decades after immigrating to America and four after serving as secretary(ˈsekriˌterē) of state, Henry Kissinger still sounds fresh(freSH) off the boat from Fürth—in what is nevertheless(ˌnevərT͟Həˈles) elaborately(əˈlæb(ə)rətli) accurate(ˈakyərit) English. (An alternative(ôlˈtərnətiv) explanation(ˌekspləˈnāSHən
), runs a joke about Mr Kissinger, is that he never listens.)

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https://www.economist.com/news/books-and-arts/21741956-new-evidence-suggests-drop-results-after-age-17-master-language