there is any online test for a ham radio and i have a friend that want to know if you need to be a us citizen

They have practice exams online, but all license exams are written.

I don't think citizenship is a requirement for an American amateur radio license. Your country may have what's called reciprocal authority with the FCC. If so, you can obtain a license in your country and it will be also be good in the US.

I would study reciprocal authority over the net since it has it's on transmission rules (in the US).

EDIT: Here's a website that gives out practice exams:

www.eham.net/exams/

I have been doing a little research for myself, and IIRC anyone can get licensed except a representative of a foreign government.

thank you