1.作为情态动词用，常用在否定句和疑问句中。

Dare (need) +S +V S + daren’t (needn’t) +V

I daren’t walk through the forest at night. Dare you walk through the forest at night? You needn’t return the book now. Need he go yesterday?

可兼做行为动词的情态动词：need 、 dare