(单词翻译:单击)
Today we will answer a question about two misunderstood modal verbs.
今天我们会解答两个易错情态动词的问题。
Modal verbs are helping verbs.
情态动词是助动词。
They help us express things like necessity, permission, ability and possibility.
可以帮助我们表达必要性、许可、能力和可能性的含义。
For example, "I can bring the bag tomorrow" uses the modal verb "can" to express ability.
比如，“我可以明天把包带来”这句话就用到了动词can（能，可以）来表达能力。
Now, here is our question:
下面是本期的问题：
Hi! Can you tell me the difference between "must" and "have to"?
您好！可以请教下“must”和“have to”的区别吗？
Hello, Manuel. Thanks for writing!
你好Manuel，感谢你的来信。
The modal verbs "must" and "have to" are very close in meaning.
情态动词“must”和“have to”的意思十分相近。
They both express a requirement or need to do something.
它们都可以表达需要做某事的含义。
First, let me tell you what grammar books say about these verbs.
首先来说一下语法书上对这2个动词的解读。
Then, I will tell you how we really use them.
然后我会告诉你如何在实际中运用它们。
Grammar books say that "Must" expresses that the speaker has decided that something is a requirement or necessity.
语法书上说：“must”表达的是讲话人已经断定某件事是有必要去做的。
And "have to" expresses that someone else has made something a requirement or necessity. An example would be a rule or law.
而“have to”表达的是其他人要求有必要做这件事，比如说规则或者法律就符合这种情况。
But, in the real world, we do not often separate the meanings this way.
但在现实生活中，我们通常不会对意思做这样的区分。
We use both modals to express that something is required or necessary.
我们用两个情态动词来表达某事是必需的或必要的。
"I must/have to go to the doctor today" is a rule or law.
“我今天必须去看医生”是规定或者法律要求。
"We have to/must pay off the loan by December" is very probable.
“我们必须在12月还清贷款”是很可能发生的事。
You have not slept since yesterday, you must/have to be tired.
你从昨天到现在一直没睡觉你一定很累。
Or to say that someone should do something.
或者表达某人应该做某事。
You have to watch this show. It's so funny.
你一定要看看这个节目。真的很有趣。
However, when speaking American English, we usually only use "must" to say that something is very likely.
不过，在美式英语中，我们通常只会用“must”来表达某件事的可能性极大。
For all other meanings, it usually sounds too formal or official.
而除此之外的其他意思，听起来通常会太正式或太官方。
And, Americans rarely use "must" in questions, except when criticizing someone: Must you chew so loud?
此外，美国人很少在问题里用“must”这个词，除非是批评他人，如：你嚼东西非要这么大声吗？
And, here is something to watch for:
下面要注意了：
The negative forms of "must" and "have to" have completely different meanings.
“must”和“have to”的否定形式意思则完全不同了。
We use the negative of "have to" when something is not required or necessary:
我们用“have to”的否定形式是在某件事并非必要的时候。
You don't have to wash the dishes. I'll wash them!
您不必洗碗了，我来洗就行了！
But "must not" or "mustn't" means that something is banned or not permitted.
而“must not”和“mustn’t”的意思是——某件事受到禁止，不允许任何人做。
And that's Ask a Teacher.
以上就是今日名师答疑的全部内容。
I'm Alice Bryant.
我是艾莉丝·布莱恩特。
