need的用法!全一些,什么时候用to do?什么时候用doing?

need 既可以作为实义动词,又可以用作情态动词。先看情态动词的用法,只用于疑问句、否定句以及暗含某种否定含义的肯定句中,没有词形的变化。如：Need I go before ten o'clock?Yes,you must/No,you don't have to/needn'tyou needn't be rude about it用作实义动词时,后面接“to do”,表示需要做某事；后面接“doing "表示被动含义,即主语需要被。。。如：He needs to water the flowersyour hair needs cutting