need作情态动词时不用于肯定句(本人至今还没见过),主要用于疑问句或否定句.没有needn't to do这样的用法,need作情态动词时后面应该是动词原形.
当见到“Need I...”或needn't时你可以判断need为情态动词;当见到need to do时可以判断它是实义动词.
needn't相当于don't need to,常用来否定回答“Must I...?”,还可以与完成式连用(needn't have done),表示“本来不必这么做(但实际做了)”.
need作情态动词时不用于肯定句(本人至今还没见过),主要用于疑问句或否定句.没有needn't to do这样的用法,need作情态动词时后面应该是动词原形.
当见到“Need I...”或needn't时你可以判断need为情态动词;当见到need to do时可以判断它是实义动词.
needn't相当于don't need to,常用来否定回答“Must I...?”,还可以与完成式连用(needn't have done),表示“本来不必这么做(但实际做了)”.