第1个回答 2010-04-26
【王子行原创】
这是我归纳的用法,既简单易懂又准确可靠
need作实义动词
sb need sth
sb need to do sth
sth need doing/to be done
这时它有人称和数的变化(needs,needed)
否定sb don't need to do
疑问Do sb need to do
作情态动词
need not do
Need sb do
无人称和数变化,只用于否定疑问句
至于什么时候用,都可以互换,如she doesn't need to do homework=she needn't do homework,关键是记住句型,祝你金榜题名
【王子行原创】
第2个回答 2010-04-22
1 .做情态动词,用法和can等情态动词一样,只是很少用于肯定句。否定直接加not,如:
you needn't work hard.
2.做实义动词。用法和want等动词一样.
you need to speak english well.
you don't need to work hard.
I need an English book.
第3个回答 2010-04-22
1)need当情态动词时,不可以用于陈述句,只用于疑问句和否定句。这是两者间最大的区别。