英语单词need用法：
In BrE there are two separate verbs need.在英国英语中有两个各不相同的动词need。
Need as a main verb has the question form do you need?， the negative you don’t need and the pastforms needed， did you need?and didn’t need.It has two meanings.*need作主要动词时， 疑问式为do you need?， 否定式为you don’t need， 过去式为needed、did you need?和didn’t need。
其含义有二：1.to require something or to think that something is necessary需要或认为有必要：Do you need any help?你需要帮助吗?I needed to get some sleep.我需要睡一会儿。
2.to have to or to be obliged to do sth必须或定要：Will we need to show our passports?我们须出示护照吗?Need as a modal verb has need for all forms of the present tense， need you?as the question form and need not(need n’t) as the negative.The past is need have， need n’t have.It is used to say that something is or is not necessary.
*need作情态动词时现在时均作need， 疑问式为need you?， 否定式为need not(need n’t) ， 过去式为need have、need n’t have， 用以表示某事有必要或没有必要：Need I pay the whole amount now?我现在必须全部付清吗?
I n AmE only the main verb is used.This leads to some important differences in the use and meaning of need in British and American English.在美国英语中， need只用作主要动词， 故need的用法和含义在英国英语和美国英语中有些重要差异。I n AmE it is more common for need to be used to speak about what is necessary， rather than about what you must do.在美国英语中较常用need表示有必要， 而非必须或定要：I d on’t need to go home yet一ir’s still early.(BrEan dAmE=it is n’tnecessary.) 我不必现在回家——时间还早。(英国英语和美国英语均为“不必”。)
you don’t need to go home yet——–we never go to bed before midnight.(BrE=you don’t have to.) 你不一定非要we never goto bed before现在回家———我们从来都是午夜后才睡觉。(英国英语意为不一定得。)The difference is even more noticeable in the pasttenses.在过去时中差别更明显：He did not need to go to hospital， but he went just to reassure himsel.(A mE) 他用不着去医院， 他去了只是想让自己放心
he need not have gone to hospital， but he went just to reassure himself(BrE点。(美国英语) He need n’t have gone to=he did something that wasn’t necessary.) 他本不必去医院的，他去了只是想让自己放心点·(英国英go to hospital after all-he only had a few bruises.语意为他做了不需要做的事。) He did not need to(BrE=he didn’t go.) 他最后无需去医院， 他只是有点碰伤。(英国英语意为他没有去。
