How to respond to an apology?

Positive:

That’s okay.

No worries.

That’s all right.

Please don’t worry about it.

I understand.

It’s not important.

I accept your apology.

You couldn’t help it.

It’s not your fault.

Negative:

I’m sorry, an apology isn’t enough.

I don’t think I can accept your apology.

I’m afraid an apology isn’t enough.