need_用法

Need的用法
一．用作实义动词
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 sth.
这是need最常见的用法之一，其后的宾语可以是名词，也可以是代词。

如：
1). We need a great deal of money now. 我们需要和多钱。

2). They don’t it any more. 他们不再需要它了。

3). Does your father need any help? 你爸爸需要帮助吗?
2．need doing 与need to be done
need后面可跟动名词作宾语，这种情况下应注意两点：
①.主动形式的动名词doing具有被动的含义；
②.该动名词可以改为其动词不定式的被动形式而句子的意义不变。

例如：
4). The door needs painting.
= The door needs to be painted. 那扇门需要油漆一下。

5). Your car needs mending.
= Your car needs to be repaired. 你的车需要维修了。

3．need to do sth.
作为实义动词，need后面需要接带to的动词不定式,表示有义务或责任去做某事。

如：
6). What do we need to take for the picnic? 野餐我们需要带些什么？
7). Will we need to show our passports? 我们需要出示护照吗？
8). You need to take good care of your mother. 你要好好照料你妈妈。

二．用作情态动词
作为情态动词的need具有情态动词的一般性质，要充分阐释作为情态动词的need的用法，务必首先说明白情态动词的特征。

情态动词的主要特征：
①．没有人称和数的变化。

不论主语是第几人称，不论主语是单数还是复数，情态都词都无形式变化；
②．不能单独充当谓语。

情态动词必须与一个实义动词一起构成复合谓语，并且这个实意动词要始终是动词原形。

③．变为否定句时只需在情态动词之后加not。

④．变为疑问句时只需将情态动词提到主语的前面。

need作情态动词无人称或数的变化，后接动词原形，多用于否定句和疑问句中。

如：You needn't worry.你不必担心。

如：由need引出的一般疑问句，肯定回答常用must或have to;否定答语常用needn't. —Need I answer the question? 我需要回答那个问题吗？
—Yes, you must. /Yes, you have to.是的，你必须回答。

/是的，你得回答。

/No, you needn't.不，不必了。

如：由must引出的一般疑问句，肯定回答用must,否定答语用needn't或don't have to。

—Must I do the work now? 我必须现在干这个活吗？
—Yes, you must /have to.是的，你必须做。

/No, you needn't /don't have to. 不，你现在不必做。

三．用作名词
need作为名词，含义为“缺乏，需要”；其复数表示“基本需要”。

要掌握两个词组：in (great) need of（急需）与meet the needs of(满足……的需要)。

例如：
13). There’s no need for yo u to try again. 你不必再尝试了。

14). The factory is in great need of funds. 那家工厂急需资金。

15). This house of the 1790’s can even meet the needs of the 21st century. 这栋18世纪90年代的房子甚至能够满足21世纪的需要。

四、didn’t need to do与needn’t have done
这两种结构既有相同点也有不同点。

相同点：都表示过去不必做某事。

不同点：didn’t need to do表示“没必要做某事，实际上也没有做”之意。

needn’t have done表示“虽然没有必要做某事，但已经做了”。

比较：
I didn’t need to get up early, because I had no work to do that morning. 那天早晨我没必要早起，因为我没什么事做。

(实际上没早起)
You needn’t have waken me up, Mum. I don’t have to go to school today. 妈妈，你本来用不着叫醒我，今天我不必上学。

(实际上妈妈把我叫醒了)
【联想】need have done表示过去本来需要做某事, 但事实上未做。

用于疑问句时意为“有必要……吗？”。

如：
Need they have done it yesterday? 他们昨天做这件事有必要吗？
【典型考例】
Mark _______ have hurried. After driving at top speed, he arrived half an hour early.
A. needn’t
B. wo uldn’t
C. mustn’t
D. couldn’t
Key: A
二、need用法回顾：
1. need作情态动词，主要用于否定句和疑问句中。

否定形式为needn’t。

对以need提出的问题作肯定回答要用must。

【典型考例】
— What sort of house do you want to have? Something big?
— Well, it ______ be big —that’s not important.
A. mustn’t
B. needn’t
C. can’t
D. won’t
Key: B
2. need作实义动词，意为“需要”。

主语为人时，常使用不定式；主语为物时，常使用句型need doing / need to be done。

【典型考例】
As a result of the serious flood, two-thirds of the buildings in the area ______. (2007 陕西)
A. need repairing
B. needs to repair
C. needs repairing
D. need to repair
Key: A
3. need作名词，意为“需要；必需品”。

常用短语和句式：in need需要；be in need of需要；there is no need (for sb.) to do sth. 没必要做某事。

【典型考例】
_____________________（没有必要）call me when you arrive. Just come up to my house. I’ll be at home all day. (there) (2011 湖北)
Key: There is / will be no need to
【巩固练习】
Ⅰ. 句型转换(每空一词)。

1. I needn’t buy a new car as my old one is still in good condition.
→ I ______ ______ ______ buy a new car as my old one is still in good condition.
2. You needn’t dress up. The restaurant is very casual.
→ ______ ______ ______ ______ ______ ______ ______ dress up. The restaurant is very casual.
3. There are lots of places of interest needing repairing in our city.
→ There are lots of places of interest needing ______ ______ ______ in our city.
4. By the way, need I come here tomorrow again?
→ By the way, ______ ______ ______ ______ come here tomorrow again?
Ⅱ. 用didn’t need to和needn’t have及所给动词的正确形式填空。

1. I ____________ (tell) her the news, for I knew that he had told her earlier.
2. I was the first to get there. I ____________ (go) there so early.
3. It being Sunday, I ____________ (go) to work. I went to the park with my daughter.
4. I ____________ (cook) so much food. Nobody was hungry.
5. As it turned out to be a small house party, we ____________ (dress) up so formally.
Key：
Ⅰ. 1. don’t need to 2. There is no need for you to 3. to be repaired 4. do I need to
Ⅱ. 1. didn’t need to tell 2. needn’t have gone 3. didn’t need to go 4. needn’t have cooked 5. needn’t have dressed。