need做情态动词

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need做情态动词

need做情态动词
need做情态动词

need做情态动词
■作情态动词:通常用在疑问句、否定句中,或与条件句、whether,hardly,nobody等连用.如:
Need he go so soon?他这么快就要走吗?
He needn’t go.他不必走.
If she wants anything,she need only ask.她想要什麽,只需说一声就行.
He wondered whether they need go there.他不知道他们是否需要去那里.
Nobody need be afraid of catching the disease.谁都不用害怕能得这种病.
注意:
1.因need不能用于肯定句,因此肯定回答要用must.如:
—Need I stay here any longer?我需要在这呆下去吗?
—No,you needn’t.不需要.
—Yes,you must.是的,需要呆下去.
2.need have done的否定式或疑问式,表示“本来不必做某事,但事实上却做了”.如:
She needn’t have come in person a call would have been enough.她本不必亲自来——打个电话来就足可以了.
Need you have paid so much?你当时真须要付那麽多钱吗?

情态动词:need do sth. need无时态和语态的变化
实意动词:need to do sth.
need根据第三人称单数加s,并且有时态变化,一般现在时need/needs,过去时needed