What’s a mistake that diaspora speakers make in your language that immediately gives them away?

Diaspora in this context meaning people who grew up in a country where your language isn’t spoken and they had to learn it at home.

For BCS:

• Making mistakes of grammatical cases

• Neutralized č/ć sounds (though this happens with some native speakers)

• Using archaic words or slang/informal terms that belong to an older generation. This one can sometimes give away where their parents are from.

• Wrong use of if or whether (They’ll say “ne znam ako je hladno” (i don’t know if it’s cold) instead of “ne znam je li je/da li je hladno” (I don’t know whether it’s cold)”

• In writing they will frequently fuse words together that are supposed to be separated, separate words that are supposed to be together, mess up accents and even spelling in a language that is phonetic.

It’s good that they try and it is so hard to learn these things if you didn’t grow up with it. Nonetheless, these are usually dead giveaways.

What about your languages?