既可做情态动词又可做实义动词的词如何使用dare need这样的词在什么情况下应当情态去用,什么时候又应当实义去用
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既可做情态动词又可做实义动词的词如何使用dare need这样的词在什么情况下应当情态去用,什么时候又应当实义去用
既可做情态动词又可做实义动词的词如何使用
dare need这样的词在什么情况下应当情态去用,什么时候又应当实义去用
既可做情态动词又可做实义动词的词如何使用dare need这样的词在什么情况下应当情态去用,什么时候又应当实义去用
一、 need的用法
1) need可用作实义动词,意为"需要;必要",后面可接名词、动名词或动词不定式等作宾语.注意"need doing"表示被动意义,相当于need to be done.例如:
I need a dictionary, so I need to go to the bookstore. 我需要一本词典,因此我要去趟书店.
How often does your hair need washing(need to be washed)? 你的头发需要多久洗一次?
2) need可用作情态动词,通常用于疑问句和否定句中,后接动词原形.这时need没有人称和数的变化,也没有时态的变化.例如:
It's only eight o'clock. Need you go so early? 才八点.你需要去这么早吗?
You needn't tell him about it as I have told him. 你不必跟他说那件事,我已经告诉他了.
3) needn't do与needn't have done的区别:
两者都表示"不必做.".但前者表示现在或将来不必做;而后者表示"过去(本来)不必做(而事实上已经做了)".例如:
You needn't carry the desks out of the classroom when you clean the classroom. 你打扫教室时不必把桌子搬到教室外.
You needn't have bought such a big TV as it takes too much room. 你本来不必买这么大的电视,它占据的空间太大了(而事实上已经买了).
二、 dare的用法
1) dare用作实义动词,此时其后的动词不定式可带to也可不带to,且dare有人称和数以及时态的变化.例如:
I dare to jump down from the top of the wall. 我敢从那墙头上跳下来.
She doesn't dare (to) meet her teacher's eyes. 她不敢与老师对视.
2) dare用作情态动词,后跟动词原形,主要用于疑问句、否定句和条件句中.例如:
How dare she do things like that to me? 她怎么敢对我做那种事?
-Dare you catch the mouse? 你敢去抓那只老鼠吗?
-I daren't do that. 我不敢抓.
If you dare say that to our teacher, I would vote for you. 如果你敢向我们的老师说那件事,我就投你一票.
做。爱