8. would
(1)委婉请求或命令
would you take a seat? 请坐!
(2)表过去习惯性动作
he would sit there for hours， doing nothing. 他常一连几个小时坐在那里，什么也不做。
(3)表过去的一种倾向
he told us that the box would not open. 他告诉我们盒子打不开。
(4)表对过去的猜测
that would be in 1966， i think. 我想那大概发生在1966年。
9. dare 和 dared
(1)敢
how dare you speak to me like that? 你怎敢那样对我说话?
no one dared speak of it. 当时没人敢谈论此事。
(2)有时后面跟不定式，用作行为动词
he dares to think， to speak， and to act. 他敢想，敢说，敢干。
10. need
(1)“需要”，用于否定句和疑问句中
need i show you my passport? ——yes， you must. 我需要出示护照吗?是的。
——no， you needn't. 不，不必啦。
we didn't need to call the doctor. 我们不必请大夫。
(2) needn't + have + pp 本不必做
she needn't have watered the flowers. 她本不必浇花。