1 used to form the negative with the verbs be, do and have (auxiliary verbs)and with verbs such as can, must, will, etc (modal verbs). Not is often pronounced or written n't in informal situations （与助动词(auxiliary verb) be、do、have及情态动词(modal verb) can、must、will等连用，构成否定式，在非正式的场合中缩写为n't）不，没有: It's not/it isn't raining now. 现在没有下雨。I cannot/can't see from here. 我从这里看不到。He didn't invite me. 他没有邀请我。Don't you like spaghetti? 你不喜欢吃意大利面条吗？I hope she will not/won't be late. 我希望她不会迟到。You're German, aren't you? 你是德国人，对吗？

2 used to give the following word or phrase a negative meaning （用于赋予后接的词或短语否定意思）: He told me not to telephone. 他叫我不要打电话。She accused me of not telling the truth. 她指责我不说实话。Not one person replied to my advertisement. 没有一个人对我的广告有回应。It's not easy. 这不容易啊。He's not very tall. 他个子不大高。

3 used to give a short negative reply （用于作简短的否定答复）: ‘Do you think they'll get divorced?’ ‘I hope not.’ (= I hope that they will not.) “你认为他们会离婚吗？”“我希望他们不会。”‘Can I borrow £20?’ ‘ Certainly not!’ “我可不可以借20英镑？”“当然不行！”‘Whose turn is it to do the shopping?’ ‘Not mine.’ “这次轮到谁去买东西？”“不是我。”

4 used with or to give a negative possibility （与or连用，表示否定的可能性）或不: Shall we tell her or not ? 我们是告诉她，还是不告诉她呢？I don't know if/whether he's telling the truth or not. 我不知道他说的是真话还是假话。

1 used as a way of replying when sb has thanked you （用于别人道谢时的回应）别客气，不用谢: ‘Thanks for the present.’ ’Not at all, don't mention it.’ “谢谢你的礼物。”“别客气，不用谢。”

2 used as a way of saying ‘no’ or ‘definitely not’ （no或definitely not的另一种说法）一点也不: ‘Do you mind if I come too?’ ‘Not at all.’ “如果我也来，你会介意吗？”“一点也不。”The instructions are not at all clear. 那些指示一点也不清楚。