I'm sorry to keep you waiting.
对不起让您久等了。
Sorry for being late.
对不起,我迟到了。
Forgive me for being rude.
请原谅我不礼貌。
That's quite all right.
没关系。
That's no problem.
没关系。
Oh,dear! I forgot all about it.
喔,天哪!我忘的一干二净。
Not to worry.
不用担心。
Don't worry about it.
不用担心。
Never mind.
不用担心。
No big deal.
没什么大不了。