How can you tell if someone is a virgin?

There is no absolutely definitive test. (There are ways other than intercourse to rupture the hymen, and vestiges can remain even after intercourse, so the presence or absence of a hymen is not necessarily conclusive.)

^generally, it not absent if shes a virgin. unless shes been masturbating for quite some time....

^.^

ask.

if its a girl, if you do it with her, and shes FOR SURE NOT ON HER PERIOD, if there's a little blood, shes a virgin. no blood not a virgin. but even if there's no blood, but she still claimed you took her virginity, she may have been raped.