WOW!

That makes for some serious studying.

Your English is certainly native;)

As a linguistics major, I think all languages are important. From the Piraha language of Brazil that has no firm numeral system to English that has a very funny way to make negations.

But it says 5 languages to choose from?

1. Chinese dialects (most noticeably Standard Mandarin)
2. Arabic (both standard and spoken dialects)
3. Russian
4. French
5. Hindi

English is too common to be noticeably important. So I wouldn't put it on the top 5.

Jilin dialect of Mandarin, bit similar to Beijing dialect, is common in South Korea. Come to think of it, Incheon (city right next to Seoul) and Pyongyang (historically) have the world's first Mandarin-only Chinatowns in the world.