(1) ①at all意为“根本(不)；全然(不)；毫不(无)”，常用来强调否定句。
- I didn't understand anything at all.
我什么也不明白。 - She wasn't at all frightened.
她根本不害怕。
②at all 也可用在问句或与if，hardly连用，有时甚至用在肯定句中，起强调作用，可译为“真的，确实”。
- Is he at all suitable for the post?
他真的适合这一职位吗？ - He'll come before dinner, if he comes at all.
如果他真要来的话，他将在饭前来。 - If it is at all foggy, I shall not go out.
如果真的有雾，我将不出去。 - I don't think he works much — if at all.
我认为他如果真干的话，也不会干多少。 - As a matter of fact, I hardly know her at all.
事实上，我根本不认识她。
③在别人说“Thank you”, “It's very kind of you”, “We're giving you a lot of trouble”等时，用Not at all，意为“不用客气”。
(2) in the least意为“一点(也不)，丝毫(不)”，有时用在条件句中。
- His mother did not in the least understand him.
他母亲一点也不理解他。 - If you are in the least doubtful about it, don't do it.
如果你对此有丝毫疑虑，就不要做。
