成人高考英语语法归纳及练习十五

来源:
江西成考网
发布日期
2007年02月14日

摘要:  情态动词(二)   内 容 提 要   情态动词有can(能),may(可以),must(必须),have to(不得不),ought to(应该),dare(敢),used to(过去经常),had better(最好),would rather(宁愿)。在肯定句中它们后边都要接 动词原形 .在否定句中,can,may,must和dare后边加not;have to和ought to分别在have和ought后加not;used to的否定式可用used not to,也可用didn't u

  情态动词(二)

  内 容 提 要

  情态动词有can(能),may(可以),must(必须),have to(不得不),ought to(应该),dare(敢),used to(过去经常),had better(最好),would rather(宁愿)。在肯定句中它们后边都要接 动词原形 .在否定句中,can,may,must和dare后边加not;have to和ought to分别在have和ought后加not;used to的否定式可用used not to,也可用didn't use to,但后者用得较多;had better和would rather的否定式分别是had better not和would rather not.这些情态动词与现在完成时连用在某种意义上有一定的虚拟性。

  情态动词与完成时的使用

  一、must+have+ED分词:用于肯定句,表示对过去情况的一种肯定推测,表示“肯定,一定”

  1) It around nine o'clock when I drove back home because it was already dark.

  [A] had to be [B] must have been [C] was to be [D] must be

  2) John's score on the test is the highest in the class;

  [A] he should study last night

  [B] he should have studied last night

  [C] he must have studied last night

  [D] he must had to study last night

  3) After searching [A] for evidence in the house,the police concluded [B] that the thief must have come in [C] through the window and stole [D] the silver while the family was asleep.

  二、may (might)+have+ED分词:用于肯定句和否定句,表示对