对不起。 Sorry.

我非常抱歉。 I‘m terribly sorry.

我对我所做的事表示抱歉。 I'm sorry for what I have done.

我真蠢。 That was stuppid of me.

我怎样才能补偿你呢？ How can I make it up to you?

我希望你会原谅我。 I hope you will forgive me.

我道歉。 I appologize.

请接受我的歉意。 Please accept my appologies.

忘了这事吧。 Forget about it.

不要紧。 It doesn't matter.

没关系。That's all right.

Saying sorry and the appropriate way to respond

Mary: I've got some bad news about the bike you lent me.
John: What's that?
Mary: I fell on the way to school,and your bike got scratched. I'm really sorry.
John: Don't worry about it. It's not new,it already has a few scratches. Did you get hurt?
Mary: No,thank you.
John: That's the most important thing.
Mary: It's kind of you to say. I feel a little stupid.
John: Forget about it.
Mary: When you lent me the bike,it looked brand new,almost anyway.
John: Maybe,but really I have fallen a couple of times and it's been hit once or twice as well.
Mary: I appreciate that,thank you.