情态动词must的用法
时间:2016-10-31 04:14:56
(单词翻译:单击)
1. 表示义务、命令或必要
主要用于用于肯定句、否定句和疑问句。具体用法如下:
(1)意为“必须”。如:
Soldiers must obey orders. 军人必须服从命令。
Something must be done to stop pollution. 必须采取措施来防止污染。(可跟被动语态)
I think I must be going. 我想我得走了。(可跟进行时态)
注:must 和have to 的用法及区别:
must 和have to 都表示“必须”,有时二者可以通用,如:
I must / have to leave now. 我得走了。
must表示说话人的主观看法,have to 表示客观的需要。如:
I feel I must write to thank you for your help. 我觉得我必须写信感谢你对我的帮助。
It is raining hard. You have to take an umbrella. 雨下得很大,你得带把伞。
must只有现在时形式;have to有更多时态。如:
We had to be there at eight. 我们八点钟必须到那儿。
“You'll have to get off here,” the conductor said. “你得在这里下车了,”售票员说。
must用于宾语从句或间接引语中也可表示过去情况。如:
He said that he must buy a gift for Mary. 他说他必须给玛丽买个礼物。
She insists that I must do it by myself. 他坚持这事我必须独立完成。
mustn't表示“禁止”“不许”;表示“不必”时,要用have to的各种形式。如:
You must not go there. 你不准去那儿。
We mustn't smoke here, must we? 我们在这儿绝不能吸烟,是吗?
We don't have to buy a new radio. 我们不必买新收音机了。
⑤以must开头的疑问句,肯定回答用must, 否定回答用needn't 或don't have to.如:
—Must I do it? 我一定要做这件事吗?
—Yes, you must. (No, you needn't. / No, you don't have to.) 是的,一定要做。(不必。)
(2)意为“应当”。如:
We must have a
discussion1 about it before making a decision. 再作决定之前我们应该讨论一下。
You must read the book. 你应该读那本书。
(3)表示必然性。如:
Man must die. 人必有一死。
What must be will be. 注定要发生的事总要发生。
(4)表示与说话人愿望相反及不耐烦,意为“偏要”“偏偏”。如:
Why must she keep on asking? 他干吗非要问个不停?
We were ready to leave, the neighbor must come and
chatter2. 我们刚准备好要走, 邻居偏偏过来聊天。
2. 表示推测
must表示推测通常只用于肯定句,意为“准是”、“一定”,在否定句或疑问句用can。 如:
(1) must+动词原形表示对现在情况的推测。如:
You must be tired after your long journey. 你走了这么远的路,一定很累。
It must be true. 那必定是真的。
The man she married must have a lot of money. 她嫁的那个人一定有不少钱。
(2) must+ have+ 动词的过去分词,表示对过去事情的推测。如:
We must have taken the wrong road. 我们一定走错路了。
He must have arrived there. 他必已到达那儿了。
(3) must+ 进行式。
表示对正在发生的事情的推测。如:
Hurry up! Mother must be waiting anxiously. 快点!妈妈一定等急了。
有时表示“即将┅”,“将要┅”如:
I must be leaving now. 我得走了。
有时must+ 进行式用来表示“老是在(干某事)”,如:
Why must you always be
finding3 fault with others? 你为什么老是挑别人的毛病?
(4) must+ 完成进行式,表示“准是一直在┅”如:
Someone must have been smoking here.一定有人一直在这里抽烟。
They are sweating all over, They must have been playing football on the playground. 他们浑身是汗,准时在操场踢足球来着。
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