need 不同用法
一、 情态动词:作为情态动词时，只能用于否定句和疑问句中,或用于由if或whether引导的宾语从句中，一般不能用于肯定句。
变为疑问句时只需将情态动词提到主语的前面，
变为否定句时只需在情态动词之后加not。
1. need do sth.
Need I buy a new book ? 我须要买本新书吗？
Yes, you must. / No, you needn't'He needn't play the piano. 他不需要弹钢琴。
2. 用need提问时，肯定回答用：must ； 否定回答用：needn't.
Need Tom do housework on weekends? Yes, he must. /No, he needn't.
3. 作为 "Must sb …?"句式的否定回答用: needn't，相当于 "… not have to". Must I fold my clothes now? 我必须现在叠衣服吗？
Yes, you must. No, you, you needn't. = No, you don't have to.
Must I hand in my homework now? Yes, you must./ No, you needn't.
二、 实义动词:作为实义动词，need后面的宾语可以是名词、动名词、动词不定式或代词，这种情况下，need既可用于肯定句，也可用于否定句和疑问句，构成否定句和疑问句时要借助于助动词do或does.
1. need n. /pron. 需要…
a.)The kids need some fruit. 孩子们需要些水果。
b.) We need a great deal of money now. 我们需要和多钱
2. need doing sth. …
= need to be done … 需要被… The young trees need watering at once. 小树需要立刻浇水。=The young trees need to be watered.
3. need to do sth. I need to take good care of my younger brother. 我要好好照料我弟弟。
三、 need作为名词，含义为"缺乏，需要"；其复数表示"基本需要"。
掌握两个词组：
in (great) need of（急需） 与
meet the needs of(满足……的需要)。
a.) There's no need for you to try again. 你不必再尝试了。
b.) The school is in great need of teachers. 这所学校急需教师。
Exercises
1. His friend needs ______（make）an effort to finish the work.
2. Need I ______(share) this apple with Tony?
3. 你不必就此事大动肝火。You ____ ___ ___ about it.
4. The dangerous houses need ___________(pull) down at once.
5. More workers ______ (need) in our factory.
6. The factory is___ ___ ___ ___ ___ money.（工厂急需资金）
答案：1. to make 2. share 3. needn't get mad 4. to be pulled / pulling
5. are needed 6. in great need of
