[shaneoh]

Can't the same argument be made of almost any language unless you live in a bilingual neighborhood?

[jeroenhd]

"unless you live in a bilingual neighborhood" is key here. Many countries across the world teach English as a second language and in western trade it's the lingua franca. Mandarin is spoken in various countries, but many of the Mandarin-speaking countries also have English as a common second language.

Going by [this list](https://en.wikipedia.org/wiki/List_of_languages_by_total_num...), you can see how if you want to expand your reach, some languages make more sense to learn than others.

[rcme]

Yes, which is why most languages are only spoken by native speaker.

[nonethewiser]

No because English is the de-facto language for trade.

[shaneoh]

Fair point, but I meant for English-native speakers in this context.

[naniwaduni]

Functionally bilingual neighborhoods are, in fact, quite common.