I'm going to break a promise
Why would you intentionally break a promise?
He didn't realize that I am unable to keep my promises. He always gave me the feeling like I had to make many efforts
Keeping promises can help build trust between people. This way the other person knows you have kept their promises in the past, so they will trust you in the future.
I haven't broken any promises. I'm a really honest person.
Well I'm glad you aren't going to break a promise anymore, that's the right thing to do.