Modal Verbs - How to Use Must, Have to and Should - English Grammar Lesson

情态动词 — 怎样使用“Must”、“Have to”和“Should” — 英语语法课程

Hi, I'm Kasia.

嗨，我是Kasia。

Welcome to Oxford Online English.

欢迎来到Oxford Online English。

In this lesson, you can learn about the modal verbs must, have to and should.

在本节课里，您可以学到情态动词 “must”、“have to”和“should”。

Do you know the difference between 'must', 'have to' and 'should'?

您知道“must”、“have to”和 “should”之间的区别吗？

English learners often mix up these three verbs.

英语学生们经常搞混 这三个动词。

In this lesson, you can learn how to use must, have to and should correctly in English.

在本节课里，您可以学怎样在英语里 正确地使用“must”、“have to”和“should”。

Must and have to are both used to talk about obligations: things you cannot choose not

“Must”和“have to”二者常用于谈论 责任：那些您不能选择

to do.

不做的事情。

For example:

例如：

We must talk to her before she leaves.

We must talk to her before she leaves.

I have to go into work early tomorrow.

I have to go into work early tomorrow.

If you say, We must talk to her before she leaves, you mean that you think this is very

如果您说“We must talk to her before she leaves”，您的意思是您认为这是

important, and you need to do it.

非常重要的，您要去做它。

When you say, I have to go into work early tomorrow, you mean that you have no choice.

当您说“I have to go into work early tomorrow”，您的意思是您没有选择。

These are both obligations, but they’re slightly different.

这是两个责任，但是 它们是略微不同的。

Can you see how they’re different?

您可以看出它们是怎样不同的吗？

The first obligation is more personal, which is why you use must.

第一个责任是更个人的，那就是 您为什么要使用“must”。

You feel that it’s necessary and important to talk to her before she leaves.

您觉得在她离开之前告诉她 那是必要且重要的。

The obligation comes from you and your feelings.

责任来自于您以及您的感觉。

What about have to?

那“have to”呢？

The second obligation is more situational, which is why you use have to.

第二个责任是更情景性的， 那就是为什么您使用“have to”。

It’s necessary to go into work early tomorrow, maybe because you have to meet a client, or

明天早一点去上班是必要的， 也许因为您必须与一个客户会面，或者

you have some important work to finish.

您有些重要的工作要完成。

The obligation comes from the situation, not from you.

责任来自于情形， 不是来自于您。

Let’s see some more examples:

我们再看些事例：

I must pay him back like I promised.

I must pay him back like I promised.

--> You made a promise, and now it’s important to you personally to keep your promise and

--> 您做了一个承诺，现在，信守您的 承诺并偿还他，那对您

pay him back.

个人而言是重要的。

He has to do a lot of homework every week.

He has to do a lot of homework every week.

--> He needs to do a lot of homework because the school gives him a lot of homework.

--> 他必须做大量的家庭作业，因为 学校给他大量的家庭作业。

It’s rare to use must to talk about obligations in spoken English.

在英语口语您使用“must” 去谈论责任是很少见的。

Native English speakers use have to much more in conversation.

母语人士在交谈中 更多地使用“have to”。

However, you can use must to talk about obligations in formal or written English.

然而，您可以在正式场合或书面 英语里使用“must”来谈论责任。

For example:

例如：

All passengers must have a valid ticket.

All passengers must have a valid ticket.

Candidates must arrive no later than five minutes before the scheduled start time.

Candidates must arrive no later than five minutes before the scheduled start time.

Want an easy answer to this?

想要这个的一个简单答案吗

Here’s an easy answer: use have to when you speak.

这里是一个简单的答案： 当您说时使用“have to”。

Using must to talk about obligations can sound very formal and strange in spoken English.

在口语里使用“must”来谈论责任 听起来非常正式且奇怪。

If you use have to when you speak, you’ll never be wrong!

当您讲话时，如果您使用 “have to”，您会从不犯错！

You can use must to talk about obligations in your written English if you’re writing

如果您在写某些更正式的东西， 您可以在您的书面英语里使用

something more formal.

“must”来谈论责任。

This doesn’t mean that you won’t hear must in conversation; actually, you’ll hear

这不意味着您不会在交谈里 听到“must”；实际上，

it a lot.

您会听到很多。

Why is this?

这是为什么？

Didn’t we just tell you not to use must in spoken English?

我们没有只告诉您在英语 口语里不要使用“must”吧？

It’s because must has many other meanings, too.

那是因为“must”也有 很多其他的意思。

Using must to talk about obligations is rare in spoken English, but you can use it for

在英语口语里使用“must”来谈论责任 是少见的，但是，您可以因为

many other things.

很多其他的事情使用它。

Okay, you’ve seen how must and have to are different.

好的，您看过“must”和“have to” 是怎么不同的。

What about mustn’t and don’t have to?

那“mustn’t”和“don’t have to”呢？

Wait, what?

等等，什么？

We just talked about must and have to.

我们刚刚谈论“must”和“have to”。

Isn’t this the same?

这不是一样的吗？

Not at all.

不完全是。

Must and have to aren’t exactly the same, but they are quite similar.

“Must”和“have to”不是完全相同的， 但是，他们是十分相似的。

However, the negatives—mustn’t and don’t have to—are completely different.

然而，否定 — “mustn’t”和 “don’t have to” — 是完全不同的。

Look at two sentences:

看两个句子：

Visitors must not touch the paintings.

Visitors must not touch the paintings.

You don’t have to be here before ten.

You don’t have to be here before ten.

Can you tell the difference?

您能说下差别吗？

Must not means that something is forbidden.

“Must not”意思是某些事情是禁止的。

You are not allowed to do this.

您不被允许做这个。

If you’re in a museum, and the sign says Visitors must not touch the paintings, then

如果您在博物馆里，标识说 “Visitors must not touch the paintings”，那么，

don’t touch the paintings!

不要触摸油画！

Don’t have to means that something is not necessary.

“Don’t have to”意思 是某些事是没必要的。

You can choose to do something or not.

您可以选择做某些事或不做。

If we have plans, and I tell you, You don’t have to be here before ten, then you can be

如果我们有计划，我告诉您，“You don’t have to be here before ten”，

here before ten if you want.

那么，如果您想，您可以 在10点前到这里。

You can come at nine, at eight, or whenever you want.

您可以在九点、八点或任何 您想的时间来。

It’s your choice.

那是您的选择。

Let’s see some more examples:

我们再看一些事例：

Passengers must not talk to the driver while the bus is moving.

Passengers must not talk to the driver while the bus is moving.

--> It’s forbidden to talk to the driver while the bus is moving; you aren’t allowed

--> 当公车在开动时，和司机交谈 是禁止的；您不被

to do this.

允许做这个。

You don’t have to finish it today.

You don’t have to finish it today.

--> You can finish it today if you want to, but you can also leave it until later if you

--> 如果您想做，您今天可以 完成它，但是，如果您想，

want.

您也可以留着它之后做。

It’s your choice.

那是您的选择。

Like must, must not is more common in formal or written English.

像是“must”、“must not”在正式的或 书面英语里是很常见的。

In spoken English, it’s more common to use can’t.

在英语口语里，使用 “can’t”是更常见的。

For example, you might see a sign saying:

例如，您也许看到一个标志说：

Mobile phones must not be used while driving.

Mobile phones must not be used while driving.

But, if you were talking, you’d probably say:

但是，如果您在交谈， 您有可能说：

You can’t use your phone while you’re driving.

You can’t use your phone while you’re driving.

On the other hand, don’t have to is common in both spoken and written English.

另一方面，“don’t have to”在英语口语 和书面英语里都是常见的。

So now you’ve seen the difference between must and have to, but what about should?

那么，现在，您看到了“must”与“have to” 之间的差别，但是，“should”呢？

Remember that must and have to can be used to talk about obligations.

记住“must”和“have to” 能用于谈论责任。

Should is different.

“Should”是不同的。

You use should to give advice or express your opinion.

您使用“should”来给出建议， 或表达您的观点。

For example:

例如：

You should go to bed earlier.

You should go to bed earlier.

Then you wouldn’t feel so tired all the time.

Then you wouldn’t feel so tired all the time.

--> This is my advice.

--> 这是我的建议。

I think it’s better for you to do this, but it isn’t necessary.

我认为做这个对您来说是更好的， 但是，那是没必要的。

It’s not an obligation, so you still have a choice.

那不是一个责任，所以 您仍然有一个选择。

He should do more work if he wants to get promoted.

He should do more work if he wants to get promoted.

--> This is my opinion.

--> 这是我的观点。

I don’t think he needs to do it, and I don’t necessarily care if he does this or not.

我不认为他需要做那个，我不必 关心他做了这个还是没有。

You can’t use should to talk about obligations or rules.

您不能使用“should”来 谈论责任或规则。

When you say,

当您说，

You should…

You should…

You mean that the person has a choice.

您意思是那个人有一个选择。

You’re giving your opinion or some advice.

您在给出您的观点或一些建议。

However, must can also be used to give advice.

然而，“must”也能用于给出建议。

For example:

例如：

You must try the fish.

You must try the fish.

It’s delicious!

It’s delicious!

Actually, you can also use have to to give advice.

实际上，您也能使用 “have to”来给出建议。

You could also say:

您也能说：

You have to try the fish.

You have to try the fish.

It’s delicious!

It’s delicious!

Can you tell the difference between using should to give advice, and using must or have

您可以说出使用“should”、“must” 或“have to”给出建议

to?

之间的差别吗？

Giving advice with must or have to is stronger and more emphatic than giving advice with

用“must”或“have to”给出建议是 比较强烈的，并比

should.

用“should”给出建议更强调。

If you say:

如果您说：

You should try the fish.

You should try the fish.

This sounds quite neutral, but if you say:

这听起来很中性，但是，如果您说：

You must try the fish!

You must try the fish!

Or, You have to try the fish!

或者，You have to try the fish!

These sound much stronger.

这些听起来十分强烈。

You’re more excited about what you’re saying.

您对您正在说的更兴奋。

You really like that fish!

您真的喜欢那条鱼。

So, you can use must, have to or should to give advice or express opinions.

所以，您可以使用“must”、“have to”或“should” 来给出建议或者表达观点。

Using must or have to expresses stronger feelings than just using should.

使用“must”或“have to”比只使用 “should”表达更强烈的感觉。

However, if you want to give negative advice, only shouldn’t is possible.

然而，如果您想给出否定建议， 只用“shouldn’t”是可能的。

For example:

例如：

You shouldn’t eat so much chocolate at once—you’ll make yourself sick!

You shouldn’t eat so much chocolate at once—you’ll make yourself sick!

You shouldn’t take the job unless you’re sure it’s what you want.

You shouldn’t take the job unless you’re sure it’s what you want.

In negative sentences, you can only use shouldn’t to give advice or express your opinion.

在否定句里，您可以只用“shouldn’t” 来给出建议或表达您的观点。

You can’t use mustn’t or don’t have to with this meaning.

您不能使用“mustn’t”或“don’t have to” 而带有这个意思。

At this point, you’ve seen how to use must, have to and should to talk about obligations

在这一重点，您看到了怎样使用“must”、 “have to”和“should”来

or advice.

谈论责任或建议。

Let’s put everything together by comparing all three verbs.

我们通过比较所有三个动词 把所有东西结合在一起。

Use must for:

您使用“must”在：

Obligations you feel strongly about: I must remember to send him a birthday card.

您强烈感觉到的责任： I must remember to send him a birthday card.

Obligations in formal, written English: All employees must wash hands.

责任的正式形式和书面英语形式： All employees must wash hands.

Strong advice: You must read it—it’s an amazing story!

强烈的建议：You must read it— it’s anamazing story!

Saying something is forbidden, if you use mustn’t: Children must not be left unattended.

如果您使用“mustn’t”，说某些事是禁止的： Children must not be left unattended.

Remember that mustn’t or must not are more formal, and in spoken English it’s more

记住“mustn’t”或“must not”是 更正式地，在英语口语里，

common to say can’t.

说“can’t”是更常见的。

Next, what about have to?

接下来，那“have to”呢？

You use have to for:

您使用“have to”在：

Obligations which depend on rules or circumstances: I have to wear glasses because I can’t see

取决于规则或情形的责任： I have to wear glasses because I can’t see

so clearly.

so clearly.

Most obligations in spoken English: Do you have to work tomorrow?

英语口语里的大部分责任：Do you have to work tomorrow?

Saying something is not necessary: You don’t have to do this if you don’t want to.

说某些事是不必要的：You don’t have to do this if you don’t want to.

Strong advice: You have to try this ice cream!

强烈的建议：You have to try this ice cream!

Using have to for strong advice sounds more conversational than using must.

“have to” 用于强烈的建议听起来 比用“must”更有对话性。

Finally, should.

最后，“should”。

You can use should for:

您可以使用“should”在：

Giving advice: You should try once more—I’m sure you can get it.

给出建议： You should try once more—I’m sure you can get it.

Giving negative advice: You shouldn’t work so hard.

给出否定建议： You shouldn’t work so hard.

Take a break sometimes!

偶尔休息一下。

Giving your opinion: If they make us work overtime, they should pay us for it.

给出您的观点： If they make us work overtime, they should pay us for it.

One last point: these three verbs can also be used to talk about probability and certainty.

最后一个重点： these three verbs can also be used to talk about probability and certainty.

In this video, we focused on talking about obligations and giving advice, but these verbs

在这部视频里，我们着重于谈论 责任、给出建议，但是这些动词

can also be used in other ways.

也能以其他方式使用。

So now you’ve seen how to use must, have to and should in different ways.

所以，现在您看到怎样以不同的方式 使用“must”、“have to”和“should”。

Want more practice with this topic?

想在这个主题有更多的练习吗

Check out the full lesson on our website: Oxford Online English.com.

在我们的网站查看完整版本： Oxford Online English.com.

You can read the script and practice with a quiz.

您可以读脚本，并做随堂测验。

Thanks for watching!

感谢观看！

See you next time!

下次见！