祈使句反义疑问句_过去完成时反义疑问句_i think反义疑问句(14)
will, would用于疑问句表示说话人向对方提出请求或询问,用 would 比 will 更婉转,客气。
7.Shall、should 表示命令,警告,允诺,征求,劝告,建议,惊奇。
8.have to,不得不,必须,表示客观条件只能如此,而must 则表示主观思想。
情态动词功能:
助动词主要有两类:基本助动词和情态助动词。
基本助动词有三个:do,have和be;
情态助动词基本的有十四个:may, might; can, could; will, would; shall, should; must, need, dare, used to, ought to.had better 上述两类助动词的共同特征是,在协助主动词构成限定动词词组时,具有作用词的功能:
1) 构成否定式:
He didn't go and neither did she.
The meeting might not start until 5 o'clock.
2) 构成疑问式或附加疑问式:
Must you leave right now?
You have been learning French for 5 years, haven't you?
3) 构成修辞倒装:
Nowhere can he obtain any information about his sister.
Hardly had he arrived when she started complaining.
4) 代替限定动词词组:
A: Who can solve this crossword puzzle?
B: Tom can.
A: Shall I write to him?
B: Yes, do.
情态动词表推测的用法小结
(一)情态动词表推测的三种句式
1.在肯定句中一般用must (一定),may(可能),might /can, could(也许,或许)。
(1)He must/may/might know the answer to this question?
他一定/可能/也许知道这个问题的答案。
(2)It is cold in the room. They must have turned off the heating.
屋里很冷,他们肯定把暖气关了。
2. 否定句中用can’t / couldn’t(不可能), may not/might not (可能不)。
(1)It can’t/couldn’t be the headmaster. He has gone to America. 这不可能是校长,他去美国了。
(2)He may not/might not know the scientist. 他也许不认识那位科学家。祈使句反义疑问句
3. 疑问句中用can/could (能……?)。
(1)Could he have finished the task?他可能把任务完成了吗?
(2)Can he be at home now? 他现在能在家吗?
注:以上三种句式中情态动词的语气按程度都是依次递减的。Might, could并非may, can的过去式,而表示语气较为委婉或可能性较小。
(二)情态动词表推测的三种时态
1. 对将来情况的推测,用“情态动词 + 动词原形”。
(1)She must / may / might / could arrive before 5. 5: 00 前她一定/可能/也许到。
(2)She must/may/might/could walk miles and miles among the hills without meeting anyone.
好坏好坏的