Does he hold open doors, pull out chairs, hold your hand. Do you just hang out watching TV. Do you spend time together that doesn't turn into sex? All signs he cares. Doe's he hang out with you and your friends. Does he cheat on you, hit on your friends, disrespect you, flirt with other women?
What you do is threaten to kill yourself and hand him a bottle of pills. You down your bottle of pills and then tell him to down his so you can be together forever and for all of eternity. If he loves you then he can't live without you, so he'll take the pills. You can use fake pills but real ones would be more romantic in my opinion.
I would look at actions rather than words. Does he try and help you when he knows you are upset or in trouble? Seem genuinely concerned about you such as when you are ill or not eating enough? Give you a lot of attention? Doesn't flirt with other girls? If so, looks like you got a genuinely caring guy, but if not.. Just trying to impress.