有人称、数和时态的变化(在变为否定句和疑问句时需借助于助动词)
(1)当主语是人时,后可接名词和动词不定式,
即:need sth./ need to do sth.
Eg: ------He needs some help.
-----It's cold outside. You need to wear more clothes.
Need 后跟不定式且用于否定句中时,表示“不必”,指没义务或没必要做某事。
Eg: ------You don't need to do it at once.
------你不必马上做那件事情。
构成疑问句或否定句时,一般使用助动词do/does。
(2)当主语为物时,后接名词或v-ing.
Eg: ------The flowers need water
----------这些花需要水。
------The flowers need watering.
------这些花需要浇水。
2.need 作为情态动词(注:情态动词不能独立作谓语,必须和动词原形一起构成谓语,
即 need 作为情态动词时,后面必须跟动词原形)
无人称、数和时态的变化,常用于否定句和疑问句中。
Eg: You needn't go this week.
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