how can a gyneacologist tell a virgin?

Answer 1

A gynecologist can tell if your hymen is broken, which usually happens upon first intercourse, although it can be broken from nonsexual behavior. Some girls also have very minimal hymens that aren't fully destroyed until they give birth.

So the gynecologist basically can't tell if you are a virgin, unless you actually have semen still in your vagina when you go for the checkup.

Answer 2

They can tell if your hymen is still intact when the visually examine you, but if your hymen has been broken by a tampon or horseback riding, etc, there is no way for them to tell.