How to tell if the guy is making empty promises or not?

is there a way to understand it ?

My last boyfriend asked me to trust me on something, when I was hesitant he told if he had a daughter he would want her to trust his boyfriend if he was like him. By the way he broke his promises. He told he wasn’t that kind of a guy who makes empty promises. He told me “not all guys all like those jerks you know, some are just nice guys!”

i sound like a fool don't i?

no ans at all!