need
1.下面三句里都用不定式：
- There is no need to hurry.
- Is there any need to hurry?
- What need is there to hurry?
把这三句里的to hurry改作of hurrying也可以，但不普通。下面三组都可以说，但每组的第一句比第二句普通：
- There is no need for you to hurry.
There is no need ofyour hurrying - Is there any need for you to hurry?
Is there any need ofyour hurrying? - What need is there for you to hurry?
What need is there ofyour hurrying?
2.the need后面接of或for和动名词比接不定式普通，如the need of （或for）doing this比the need to do this普通。
3.There is need后面接for和名词，如There is need for more money和There is urgent need for more schools。a need后面接for或of和名词，如There is a need for（或of）more money，There is a need for（或of）improvement和We are well aware of a real need today for（或of）this sort of book。no（或some，或any，或not much）need后面接for或of和名词，如There is no need for（或of）more money和There is not much need for（或of）that sort of thing。the need后面接for或of和名词，如He spoke of the need for（或of）more money和The need for（或of）further research is keenly felt。
4.have need of（需要）和have need for都可以说，have no need of和have no need for也都可以说。
5.in need of里的of不可改作for。
6.have need to...（不定式）作“必须…”解。例如：He has need to work hard to catch up. 这语的过去式当然是had need to...（不定式）。但另有had need一习语，作“应该…”解，后面的不定式通常没有to，但有时也有to。例如：You had need (to) be very careful. 这语里的had在形式上虽然属于过去时态，却并不指过去。have need to...（不定式）和had need现在都不很普通。
7.if need be属于现在虚拟语气。例如：I shall be ready to do this, if need be. if need were属于过去虚拟语气。例如：I should be ready to do this, if need were. 注意不可说if need is或if need was。if need be和if need were现在都不很普通。
8.need（动词）后面的动名词一定属于主动语态，但它的意思一定是被动的，如The watch needs winding up里的winding不可改作being wound，但它的意思却是being wound。假使把动名词改作不定式，便该说The watch needs to be wound up，不可说The watch needs to wind up。need（动词）后面的动名词的意思既然一定是被动的，所以不可说I need winding the watch up，该把winding改作to wind。比较下面四句：
- This sentence needs explaining.（不可把explaining改作to explain）
- This sentence needs to be explained.（不可把to be explained改作to explain）
- You need to explain this sentence.（不可把to explain改作explaining）
- You need explaining.（这句的意思是：“你需要被人解释一下。”它的结构跟第一句相同。）
谚语The best horse needs breaking, and the aptest child needs teaching（1.即使最好的马也需要受驯。2.即使最聪明的孩子也需要受教育）的结构也跟第一句相同。
下面每组里的两句意思相同：
- He does not need looking after.(他不必受照顾。)
He needs no looking after. - That does not need accounting for.(那个不必解释。)
That needs no accounting for.
但下面第二句远不及第一句自然，因为telling...并不是一个单纯的动作：
- He does not need telling how to take notes.
- He needs no telling how to take notes.
9.need是现在式，但在用作助动词的时候可以在疑问句和否定句里指过去，后面的不定式没有to。例如：
- Need he go yesterday?
- He need not go yesterday.
He need not have any help from us yesterday.（或He need have no help from us yesterday.）
这三句可以改作：
- Did he need to go yesterday?
- He did not need to go yesterday.（或He needed not to go yesterday.）
- He did not need to have any help from us yesterday.（或He needed not to have any help from us yesterday. 或He needed to have no help from us yesterday.）
不可说：
- Need he to go yesterday?
- He need not to go yesterday.
- He need not to have any help from us yesterday.（或He need to have no help from us yesterday.）
也不可说：
- Did he need go yesterday?
- He did not need go yesterday.（或He needed not go yesterday.）
- He did not need have any help from us yesterday.（或He needed not have any help from us yesterday. 或He needed have no help from us yesterday.）
我所说的“否定句”不一定有not或no，hardly，scarcely，only和but也是有否定的意味的词，如He need hardly（或scarcely）go yesterday和He need only（或but）have a little help from us yesterday或He need have only（或but）a little help from us yesterday。
下面各句里用need而不用needed，后面的不定式没有to，因为各句都多少有些否定或疑问的意味：
- All he need do was to inquire.
- David said his idleness was the only thing about him that he need feel ashamed of.
- She wanted me to tell her whether she need copy her composition again.
- I wondered if he need wait any longer.
但各句里的need...也可以改作needed to...。
除了在疑问句和否定句以外，need不可用作助动词，如不可说He need go yesterday和He need have much help from us yesterday，该把need go改作needed to go，把need have改作needed to have。在事实上用needed不及用had to...普通，如had to go和had to have。
Did he need any money yesterday和He did not need any money yesterday两句里的need把名词money做宾语，决不可把它改作助动词而说Need he any money yesterday和He need not any money yesterday。
10.need指过去是助动词，已经在9里讲过。need在不指过去的时候也可以用作助动词，也用在疑问句和否定句里，后面的不定式没有to，在第三人称不加s。例如：
- Need he go today?
- He need not go today.
- He need not have any help from us today.（或He need have no help from us today.）
这三句可以改作：
- Does he need to go today?
- He does not need to go today.
- He does not need to have any help from us today.
不可说：
- Need he to go today?（或Needs he to go today?）
- He need not to go today.（或He needs not to go today.）
- He need not to have any help from us today.（或He needs not to have any help from us today. He need to have my help from us today. 或He needs to have no help from us today.）
也不可说：
- Does he need go today?
- He does not need go today.（或He needs not go today.）
- He does not need have any help from us today.（或He needs not have any help from us today. 或He needs have no help from us today.）
下面两句也可以说（算作否定句）：
- He need hardly（或scarcely）go today.
- He need only（或but）have a little help from us today.（或He need have only［或but］a little help from us today.）
但也可以说He needs only（或but）to have a little help from us today和He needs to have only（或but）a little help from us today。
下面各句里用need而不用needs，后面的不定式没有to，因为各句都多少有些否定或疑问的意味：
- All he need do is to inquire.
- He says his idleness is the only thing about him that he need feel ashamed of.
- She wants me to tell her whether she need copy her composition again.
- I wonder if he need wait any longer.
但各句里的need...也可以改作needs to...。
除了在疑问句和否定句以外，need不可用作助动词，如不可说He need go today或He need have much help from us today，该把need go改作needs to go，把need have改作needs to have。在事实上用needs不及用must或has to...普通，如must go和must have，has to go和has to have。
Does he need any money today和He does not need any money today两句里的need把名词money做宾语，决不可把它改作助动词而说Need he any money today和He need not any money today。
He need not go today往往含有“我允准他今天不去”的意思，He does not need to go today并没有这含意。
11.在9里所举的Need he go yesterday和He need not go yesterday两句里的need指过去。在10里所举的Need he go today和He need not go today两句里的need并不指过去。假使单说Need he go或He need not go，当然不能断定那need是否指过去，必须看了上下文才能确定。
12.在9里所举的Need he go yesterday改作Need he have gone yesterday也可以，He need not go yesterday改作He need not have gone yesterday也可以。
He need not have gone yesterday含有“可是他竟然去了”的意思。If he had known that she was not at home, he need not have gone to see her yesterday里的need not have gone不可改作need not go或did not need to go。
13.关于need not跟must not等的区别，参见must 2
14.need not...to...（不定式）或do not need to...（不定式）to...（不定式）作“不必…才能…”解，就是“也许不…而也能…”的意思。例如：
You need not be（或do not need to be）rich to help others.（你不必富了才能帮助别人，你也许不富而也能帮助别人。）
One need not be（或does not need to be）an artist oneself to appreciate a work of art.（1.一个人不必自己是艺术家才能鉴赏艺术品。2.一个人也许自己不是艺术家而也能鉴赏艺术品。）
15.need only（或but）...to...（不定式）或only need...to...（不定式）作“只须…就会…”解。例如：
You need only（或need but，或only need）look round you to see how hard most people work.（你只须向四周看看就会见到大多数的人们怎样辛劳地工作。）
One need only（或need but，或only need）consider the question carefully to be suprised that it has not yet received due attention.
（一个人只须把这个问题仔细考虑一下，就会感觉奇怪它还不曾受到应有的注意。）
