You’re never too old to become fluent in a foreign language

The commentary misrepresents the original study as much as the popular press coverage it criticizes.

From the Abstract of the study:

“grammar-learning ability...is preserved almost to the crux of adulthood (17.4 years old) and then declines steadily”

“The results support the existence of a sharply-defined critical period for language acquisition”

From the commentary:

“It’s not even true that young children learn languages faster than older children or adults”.