“One language sets you in a corridor for life. Two languages open every door along the way.” — meaning, and did Frank Smith say it?

The line is credited to Frank Smith (1928–2020), the psycholinguist best known for his work on reading, and quotation sites link it to his 1990 book To Think. We could not open To Think to confirm the wording or page, so we list it as attributed. It means one language keeps you on a single path, while a second opens many others.

What it means

With one language you move through life down a single corridor: you reach only the people, books and ideas that language leads to. A second language adds doors all along that corridor, to other people, cultures and ways of seeing.

Where it comes from

Frank Smith was a psycholinguist who wrote widely on reading, thinking and learning; To Think (1990) is one of his books. Quotation sites credit this line to that book, but none of them gives a page, and we were not able to see the book's text. We therefore cannot confirm that the sentence is in it, or in exactly this form.

Quotation sites and English-teaching materials credit the two sentences to Frank Smith, and we found no evidence that the line came from anyone else. Until the passage is located in Smith's own writing, it is best described as attributed to him.

Questions

Who said “One language sets you in a corridor for life”?

It is credited to Frank Smith, the psycholinguist (1928–2020), and usually linked to his book To Think (1990). We could not confirm the passage in the book itself.

What does the quote mean?

One language keeps you on a single path through life; learning a second one opens doors along the way, to other people, cultures and ideas.

Is it definitely in To Think?

Not confirmed. Quotation sites name the book but give no page, and we could not view the text. That is why it is marked Attributed rather than Sourced.