A phrase used to express an apology for an action.
A phrase used to ask for clarification of something said if it is unexpected, odd or seen as rude without context.
A phrase used to request something, for example if a statement was not heard.
Don't let it bother you; put it out of your mind.
I don't want to continue with this conversation (usually used in frustration or anger).
It doesn't matter.
A conventional reply to an expression of gratitude.
Absolutely not; I forbid it or it is impossible.