改過 mend one's ways; correct one's mistakes 他確有改過表現。 he has really corrected his mistakes
過不去 1.(不能通過) cannot get through; be unable to get by; be impassable:道路阻塞了,車子過不去。the road was blocked, no car could pass.2.(為難) find fault with; be hard on; make it difficult for; embarrass 他有意跟我過不去。 he deliberately made things difficult for me. 我們批評你, 是為了幫助你, 絕不是跟你過不去。 we criticized you because we wanted to help you, not in order to find fault with you. 他老和我過不去。 he picks on me all the time.3.(過意不去) feel sorry 不必十分過不去。 don't take it so much to heart. 讓大家等了這么半天, 我心里很過不去。 i'm awfully sorry to have kept you all waiting for such a long time