Question

french question?
how do u say "it's your friend."?

Answer 1

C'est ton ami.

Answer 2

or if it's formal "C'est vos ami"

ton is the informal "your" (used for conversational speaking)
vos or votre is the formal "your" (used for formal)

Answer 3

'friend' is singular, hence formal translation would be : "C'est votre ami."

But if the friend is a 'she', then you have to write:
"C'est ton amie." or "C'est votre amie."