IPhone problems sprint to at&t?

I got a brand new iPhone 5c I bought off a women and the problem is its sprint I want to give it to someone as a gift but they have a contract with AT&T so can this sprint iPhone be used with AT&T some people have told me yes and some said no so i don't know if I should just sell it or keep it or what please help!

As long as it is not a phone that was reported stolen, AT&T can set it up