情态动词后跟动词原形.
·can和could
·may和might
·must和have to
·dare和need
·shall和should
·will和would
·ought to
·used to,had better,would rather
·can (could),may (might),
·must,need,ought to,dare (dared
·ought,will ,Shall,should,have to
补充：刚刚系统提供我的答案跟别人重复了,我要补充的是我不是抄袭的,