How to Use Must in English - English Modal Verbs

英文文法 — 情態助動詞 MUST

Hi, I’m Oli.

嗨，我是Oli。

Welcome to Oxford Online English!

歡迎來到Oxford Online English！

In this lesson, you can learn about the verb 'must'.

在本節課裡，您可以學到動詞 “must”。

'Must' can have many different meanings in English.

“Must”在英文裡可以有 很多不同的意思。

In this video, you can learn about the different meanings of 'must', and how to use 'must'

在本影片裡，您可以學動詞“must”的不同 意思，以及怎樣在

in English.

英文裡用“must”。

Part one, using 'must' to talk about obligations.

第一部分，用“must”來談論責任。

First, you can use must to talk about obligations and rules.

首先，您可以用“must”來談論 責任和規則。

For example:

例如：

"I must remember to call her—it’s her birthday."

"I must remember to call her—it’s her birthday."

This is an obligation.

這是一個責任。

It’s very important to me.

那對我很重要。

"All passengers must hold a valid ticket."

"All passengers must hold a valid ticket."

This is a rule.

這是一個規則。

You can't choose to travel without a ticket.

您不能沒有機票就去旅行。

These are things that it is necessary or important to do.

有些事是有必要做的或重要的。

If you must do something, you have no choice.

如果您必須要做某些事，您沒有選擇。

When you use must for obligations, it can mean that the obligation is important to you

在您用"must"來談責任時，它可以 意味著責任對您個人

personally.

而言很重要。

It’s not just a rule that someone else made; using 'must' means that something matters

那不僅僅是其他人制定的規則； 用“must”意味著某件事

to you.

對您很重要。

For example:

例如：

"You must be here on time, otherwise we’ll miss the start."

"You must be here on time, otherwise we’ll miss the start."

Using 'must' shows that you care about whatever you’re going to see.

用“must”顯示您在乎您 會看到的東西。

Maybe you’re going to see a concert that you’ve been looking forward to for ages,

也許您會看到一場您已期盼 很多年的演唱會。

and you’ll be really unhappy if you miss even a minute of it.

如果您錯過了那怕一分鐘， 您會真的很不開心。

"I must finish this work today."

"I must finish this work today."

Again, this means that I feel strongly about this.

同樣，這意味著我對此深有感觸。

Maybe I promised someone that I would finish it by today, and it’s important to me that

也許我承諾某人我今天會完成 它，履行承諾對我

I keep my promise.

而言是很重要的。

When talking about rules, we mostly use 'must' in formal or written English.

在談論規則時，我們在正式英文或書寫 英文裡大部分用“must”。

For example:

例如：

"All candidates must show valid ID."

"All candidates must show valid ID."

This is a rule probably in an examination hall, which of course is a formal setting.

這有可能是一個考試大廳的規則， 當然是一個正式的規定。

"Employees must wash their hands before working with food."

"Employees must wash their hands before working with food."

This could be from a sign in a restaurant or café.

這可能來自一間餐廳 或咖啡館的警示語。

Again, this is more likely to be written than spoken.

同樣，這更像是書寫的， 而不是口頭的。

In informal English, we mostly use the verb 'have to' to talk about rules and obligations.

在非正式英文裡，我們大部分用動詞 “have to”來談論規則和責任。

To review, you can use 'must' to express an obligation if the obligation is important

要複習，您可以用“must”來表達一個責任， 如果責任對您而言是

to you personally, or if you want to sound more formal.

重要的，或如果您想聽起來 更正式。

Part two, using 'must' to talk about prohibition.

第二部分，用“must”來談論禁止。

You can use 'mustn’t' to say that something is not allowed or forbidden.

您可以用“mustn’t”來說某件事 是不被允許的或是禁止的。

This is the opposite of using must to talk about obligations or rules, and is similar

這是用“must”談論責任和規則的相反意思， 在意思上

in meaning.

是相似的。

Look at some examples:

看一些例句：

"You mustn’t smoke here."

"You mustn’t smoke here."

That means smoking is forbidden; it’s against the rules to smoke here.

那意思是禁止吸煙；它是 允許吸煙的相反規則。

"Mobile phones must not be used while the plane is flying."

"Mobile phones must not be used while the plane is flying."

Again, this means that it’s forbidden to use phones.

同樣，這意思是禁止使用電話。

'Must' expresses the idea that you don’t have a choice.

“Must”表達了您不能 選擇的意思。

If you mustn’t smoke here, then it’s not OK to smoke, and you don’t have a choice.

如果您不能在這吸煙，那麼不可以吸煙， 您沒有其他選擇。

'Mustn’t' with this meaning is similar to 'can’t'.

“Mustn’t”有與“can’t”相似的意思。

With obligations and rules, we mostly use 'must' in formal or written English, and 'have

如前所述，我們在正式英文或書寫 英文裡大部分“must”搭配

to' in informal English, as we said before.

責任和規則，在非正式英文裡 則用"have to"。

However, you can use 'mustn’t' in both formal and informal English.

然而，您可以在正式和非正式 英文裡用“mustn’t”。

Part three: using 'must' to give strong advice.

第三部分：用“must”來強烈建議。

'Must' can be used to give someone advice or a recommendation.

推薦或給某人建議時 可以用“Must”。

For example:

例如;

"You must read this book—it’s amazing!"

"You must read this book—it’s amazing!"

"If you go to Paris, you must take a walk by the river at night."

"If you go to Paris, you must take a walk by the river at night."

"We must hire some new staff as soon as possible."

"We must hire some new staff as soon as possible."

In these examples, ''must' has a strong meaning.

在這些例子裡，“must”表達了強烈的意思。

If I say:

如果我說：

"You must read this book—it’s amazing!"

"You must read this book—it’s amazing!"

I don’t mean that you have an obligation to read it.

我的意思不是您有 要讀的責任。

I mean that I really, really recommend this book.

我的意思是我真的 推薦這本書。

In the same way, if I say:

用同樣的方式，如果我說：

"If you go to Paris, you must take a walk by the river at night."

"If you go to Paris, you must take a walk by the river at night."

This is advice or a recommendation.

這是建議或一個推薦。

It doesn’t mean that it’s a rule or an obligation.

那沒有它是一個規則 或一個責任的意思。

Sometimes, the meaning of 'must' depends on the context.

有時，“must”的意思取決於上下文。

For example:

例如：

"We must hire some new staff as soon as possible."

"We must hire some new staff as soon as possible."

'Must' here could mean that hiring new staff is necessary, and it’s an obligation, or

“Must”在這裡意思是聘僱新人員是 必要的，這是一個責任義務，

it could be a strong recommendation.

或者它可以是很強烈的推薦。

How do you know what 'must' means in a sentence like this?

您怎麼知道“must”在這樣的 句子裡意思是什麼？

In a sentence like this, in a lesson, where there’s no context, you can’t say exactly

課堂上，在像這樣的沒有上下文的 一個句子裡，您不能

what 'must' means.

準確地說出“must”意思是什麼。

In real life, the meaning would depend on the context: who’s speaking, what the situation

在真實生活裡，意思取決於 上下文：誰在說、情形是

is, and so on.

什麼等等。

When you use 'must' in this way, you can’t use the negative.

在您以這種方法來用“must”時， 您不能用否定式。

There’s no way to use 'mustn’t' to give advice or make recommendations.

不能用“mustn’t”來推薦和 提出建議。

Only the positive form—'must'—can have this meaning.

僅僅肯定形式 — “must” — 可以有這個意思。

Part four: using 'must' to talk about logical necessity.

第四部分：用“must”來談論 邏輯上的必要性。

Finally, 'must' can be used to make deductions.

最後，“must”可以用於推論。

What are deductions?

推論是什麼？

Well, look at some examples, and then I’ll explain what this means:

好，看一些例句，然後我會解釋 這是什麼意思：

"They must be rich.

"They must be rich.

Their house is huge!"

Their house is huge!"

"It must be a difficult exam—only 10% of candidates pass."

"It must be a difficult exam—only 10% of candidates pass."

"It must have rained last night."

"It must have rained last night."

Take the first sentence:

看下例一：

"They must be rich.

"They must be rich.

Their house is huge!"

Their house is huge!"

Do we know they’re rich?

您知道他們是富有的？

No, we don’t know for a fact.

沒有，我們不知道事實。

But, we do know that they have a huge house.

但是，我們知道他們有很大的獨立屋。

Huge houses cost a lot of money.

很大的獨立屋值很多錢。

Therefore, they must be rich.

因此，他們肯定有錢。

We’re sure that they’re rich, because otherwise they couldn’t afford such a big

我們確信他們是富有的， 否則他們負擔不起

house.

這一個大獨立屋的開銷。

Compare:

比較：

"They must be rich."

"They must be rich."

"They’re rich."

"They’re rich."

What’s the difference?

區別是什麼？

"They’re rich" is a fact.

"They’re rich" 是一個事實。

We know they’re rich.

我們知道他們是富有的。

Maybe you’re their accountant, and you know all about their financial situation.

也許您是他們的會計師，您知道 他們所有的財務狀況。

Maybe they told you how much money they have directly.

也許他們直接告訴您他們 有多少錢。

Anyway, however you know, you know they’re rich.

反正，無論如何，您知道， 您知道他們是富有的。

"They must be rich" is a deduction.

"They must be rich" 是一個推論。

You don’t actually know they’re rich.

實際上您不知道他們是富有的。

You know something else; you know that they have a huge house and this makes you sure

您知道某些其他事情，您知道他們有 很大的獨立屋，這樣您

that they’re rich.

確信他們是富有的。

Okay, let’s look at another example:

好了，我們看另一個例句：

"It must be a difficult exam—only 10% of candidates pass."

"It must be a difficult exam—only 10% of candidates pass."

Again, using 'must' expresses a deduction.

同樣，用“must”表達一個推論。

If you say this, you haven’t actually taken the exam.

如果您這麼說，您實際上 沒有參與測驗。

You don’t know for yourself that it’s difficult.

您自己不知道它是難的。

However, you do know something else: you know that only 10% of candidates pass, and this

然而，您知道某些其他事情：您知道 只有10%候選人通過了，並且這

makes you sure that it’s a difficult exam.

會讓您確信那是一個難的測試。

In our last example:

在我們的最後一個例句裡：

"It must have rained last night."

"It must have rained last night."

Did you see it rain?

您看到下雨了嗎？

No, you didn’t.

沒有，您沒有看到。

But, you’re sure it rained.

但是，您確信下雨了。

How?

怎麼確定的？

Probably, you can see that the ground is wet.

有可能，您可以看到地面是濕的。

You didn’t see or hear the rain, but you can make a deduction from what you see.

您沒看到雨或聽到雨聲，但是您可以依據 您看到的東西來推論。

What you see makes you sure that it rained last night.

您看到的讓您確信昨晚有下雨。

You can also use 'must not' with this meaning, but you can’t use the short form 'mustn’t'

您也能用“must not”搭配這個意思， 但是您不能在標準英文裡

in standard English to express the idea of deduction.

用短寫形式“mustn’t”來 表達推論的想法。

'Mustn’t' is only used to say that something is forbidden.

“Mustn’t”是僅用於說某件事 是禁止的。

Okay, that's a strange point, so let's look at our next topic, which is negatives--part

好的，這是一個奇怪的要點，所以 我們在下一個主題裡來看看它，

five.

那是否定的—第五部分。

It’s important to remember that when you use 'must' with different meanings, the negative

那對您記得什麼時候用有不同 意思的“must”很重要，否定

(or opposite) word is also different.

（或相反意思）的單詞也是不同的。

Okay, let's look at this.

好，我們看看這個。

So, if 'must' is used for obligation, the opposite would be 'mustn't', or maybe 'can't'.

那麼，如果“must”用於責任，相反意思會是 “mustn't”，或者也許“can't”。

The opposite of 'mustn't' for prohibition would be 'must' or maybe 'have to'.

“mustn't”用於禁止的相反意思會是 “must”或也許是“have to”.

The opposite of 'must' for strong advice is 'shouldn't'.

"must"用於強烈建議的相反意思 是“shouldn't”。

And for making deductions, the opposite of 'must' would be 'can't', 'couldn't', or maybe

用於推論，“must”的相反意思會是 “can't”、“couldn't”、或也許是

'must not'.

“must not”。

For example:

例如：

"Passengers must place bags above the seats."

"Passengers must place bags above the seats."

Here, 'must' expresses an obligation.

在這裡，“must”表達了一個責任。

The opposite would be:

相反意思會是：

"Passengers must not place their bags above the seats."

"Passengers must not place their bags above the seats."

Or, if you wanted to explain this rule in spoken English, you might say:

或者，如果您想口頭 解釋這個規則，您可能說：

"You can’t put your bag above your seat."

"You can’t put your bag above your seat."

Another example:

另一個例句：

"You mustn’t say anything to her."

"You mustn’t say anything to her."

Here, 'must' expresses prohibition.

在這裡“must”表達了禁止。

The opposite is:

相反意思是：

"You must say something to her."

"You must say something to her."

Or:

或者：

"You have to say something to her."

"You have to say something to her."

Finally, if you say:

最後，如果您說：

"He must be awake.

"He must be awake.

It’s two o’clock in the afternoon!"

It’s two o’clock in the afternoon!"

Here, 'must' expresses a deduction.

在這裡，“must”表達了一個推論。

The opposite could be:

相反意思可以是：

"He can’t be awake.

"He can’t be awake.

He never gets up before the late afternoon."

He never gets up before the late afternoon."

Or perhaps:

或可能是：

"He must not be awake.

"He must not be awake.

He never wakes up early."

He never wakes up early."

It’s important to remember that these opposites are not all the same!

記住這些相反意思並不是都 一樣的很重要！

For example, if you use 'must' to express prohibition, the possible opposites are 'must'

例如，如果您用“must”來表達禁止， 可能的相反意思是“must”

and 'have to'.

和“have to”。

This doesn’t mean 'must' and 'have to' have the same meaning.

這並不意味著“must”和 “have to”有相同的意思。

Modal verbs are complicated.

情態助動詞是複雜的。

For now, you need to remember one important point:

至於現在，您需要記住 一個重點：

Different meanings of 'must' have different negatives.

不同意思的“must”有不同的否定形式。

OK?

好了嗎？

Good!

好的！

Let’s look at one more point.

我們再來看一個重點。

Part six: past forms.

第六部分：過去式。

Like with negatives, if you want to use must to talk about the past, the past form depends

像是搭配否定意思，如果您想用“must”來 談論過去，過去式取決於

on the meaning of 'must'.

“must”的意思。

Often, you need to use a different verb.

通常，您需要用不同的動詞。

Take a look:

看一看：

So, 'must' for obligation, the past form is 'have to'.

所以“must”表達禁止，過去式 是“have to”。

'Mustn't' for prohibition, the past form is 'couldn't'.

“Mustn't”表達禁止，過去式 是“couldn't”。

'Must' for strong advice or recommendations, the past form is 'should have'.

“Must”表達強烈建議或推薦， 過去式是“should have”。

And for making deductions, the past form is 'must have'.

要表達推論，過去式 是“must have”。

Using 'must' with a past meaning is only possible if you are using 'must' to make deductions.

如果您用“must”來推論，用有 過去意思的“must”是可能的。

In all other cases, you need to use a different verb to talk about the past.

在所有的其他事例裡，您需要用 不同的動詞來談論過去。

Let’s look at some examples:

我們來看一些例句：

"We must be there at 9.00 tomorrow."

"We must be there at 9.00 tomorrow."

This is an obligation.

這是一個責任。

In the past, you'd say, "We had to be there at 9.00 yesterday."

在過去式，您要說："We had to be there at 9.00 yesterday."

"We mustn’t smoke in the restaurant."

"We mustn’t smoke in the restaurant."

That's prohibition.

是禁止。

The past: "We couldn’t smoke in the restaurant."

過去式： "We couldn’t smoke in the restaurant."

"You must try the stew—it’s delicious!"

"You must try the stew—it’s delicious!"

This is advice.

這是建議。

The past form: "You should have tried the stew—it was delicious!"

過去式："You should have tried the stew—it was delicious!"

"They must be on the subway—I can’t get through on the phone."

"They must be on the subway—I can’t get through on the phone."

That's a deduction.

那是推論。

The past form: "They must have been on the subway—I couldn’t get through on the phone."

過去式："They must have been on the subway—I couldn’t get through on the phone."

You can see how you need to use different verbs to talk about the past, depending on

您可以看到您要怎樣依據“must” 的不同意思來用不同的

the meaning of 'must'.

動詞談論過去。

Okay, finally, let's do a review.

好的，最後，我們來複習一下。

Let’s review what we’ve studied in this lesson.

我們複習在本節課學到了什麼。

'Must' can be used to express obligation and prohibition, to give strong advice, and to

“Must”可以用於表達責任和禁止， 來給出強烈的建議，

make deductions.

以及推論。

In some cases, 'must' is similar to other verbs.

在一些事例裡，“must”類似 於其他動詞。

For example, 'must' used to express prohibition is similar to 'can’t'.

例如，“must”用於表達禁止是 類似於“can’t”。

However, remember that similar does not mean the same!

然而，記得類似並非意味著相同！

'Must' is unique, and no verb is ever exactly the same as 'must'.

“Must”是獨特的，沒有動詞與 “must”完全相同。

Different meanings of 'must' have different negative and past forms.

“must”的不同意思有不同的 否定和過去式。

In other words, the way you use 'must' depends on the meaning of 'must'.

換句話說，您用“must”的方式取決於 “must”的意思。

You can’t just use 'must' in the same way in every sentence; you need to think about

您不能在每一個句子裡以相同的 方式用“must”；您要考慮

what 'must' means in each case.

“must”在每個事例裡的意思是什麼。

Do you want more practice with this topic?

您想有更多與這個主題有關的練習嗎？

Check out the full version of the lesson on our website: www.oxfordonlineenglish.com.

在我們的網站看課程的完整版本： www.oxfordonlineenglish.com

The full lesson includes notes and exercises to help you practise what you’ve learned

完整課程包括筆記和練習， 幫您練習在本節課裡

in this class.

學到的東西。

That’s the end of the lesson.

本節課就到這裡。

Thanks very much for watching!

非常感謝觀看！

I hope it was useful for you.

我希望那對您有用。

I'll see you next time!

我們下次見！

Bye bye.

再見！