为你解答如下：
1、情态动词有may,might,can ,could ,will ,would ,must ,shall,should,need,dare ,ought to等,表示说话人的态度.有一条语法规则想必你也知道：情态动词后面接的动词必须是原形.至于具体的用法与它们之间的区别,请在网上查阅“助动词,be动词,情态动词分别是哪些?”这篇文章.
2、dare和need这两个动词除了作情态动词,还会作实义动词.need作情态动词的例子有：
I don't think we need ask him.
Nothing need be done about this till next week.
You needn't worry - I'm not going to mention it to anyone.
作实义动词时,它的用法很灵活,如：
The doctor said I needed an operation.医生说我需要做手术.
I need to go to the toilet.我得上厕所.
This room needs brightening up a bit.这个房间需要做得更明亮一点.
She needs her hair washed.她得洗洗头.
3、dare的用法不好梳理清楚,例子：
Dare you tell him the news?（dare作情态动词）
Everyone in the office complains that he smells awful,but nobody dares (to) mention it to him.（这一句中dare是实义动词,因为是三单式,但是它又可以跟不带to的动词动词不定式.）
Do you dare (to) tell him the news?（这一句中dare是实义动词,因为已经出现助动词do,但是它也可以跟不带to的动词不定式.）
总结一点：dare不管作实义动词还是情态动词,后面都可以接动词原形（或者不带to的动词不定式）.
（注：以上例句均来自剑桥在线词典.）