need什么时候是情态动词,什么时候是行为动词,怎么区分?

1。need 做情态动词的时候,无人称或数的变化,后接动词原形,一般用于否定句和疑问句中,不用在肯定句。如：You needn't go there。Need I go with you?2。need 作为行为动词有人称和数的变化,后面可接名词,代词、动名词及带to 的动词不定式；可用于肯定句、疑问句和否定句中。如：。She needs help。(接名词)Your hair needs cutting。(动名词)You don't need to go there。（动词不定式）Does she need to go with you?