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

Summary

This Oxford Online English lesson clarifies the use of 'must', 'have to', and 'should'. 'Must' denotes personal obligation or strong advice, often formal in speech but common in writing. 'Have to' reflects situational obligations, prevalent in conversation and informal writing. 'Should' offers advice or opinions, with 'mustn’t' and 'don’t have to' indicating prohibition and non-necessity, respectively. The lesson distinguishes nuances between these modal verbs, guiding English learners to use them correctly in various contexts.

Takeaways

• 📚 Must and have to are used for talking about obligations, but they carry different nuances.
• 🤔 'Must' is more personal and expresses a sense of necessity from the speaker's perspective.
• 🏢 'Have to' is situational, indicating an obligation due to external circumstances or rules.
• 🗣️ 'Must' is less common in spoken English, while 'have to' is more frequently used in everyday conversation.
• 📝 In formal or written English, 'must' is often used to express obligations, such as in signs or official instructions.
• 🚫 'Must not' and 'don’t have to' have distinct meanings; 'must not' indicates prohibition, whereas 'don’t have to' suggests optionality.
• 🤷‍♂️ 'Should' is used to give advice or express opinions, rather than to denote obligations or rules.
• 🌟 When giving advice, 'must' or 'have to' can convey stronger feelings or emphasis than 'should'.
• 🚫 For negative advice, only 'shouldn’t' is used, not 'mustn’t' or 'don’t have to'.
• 📉 'Must' and 'have to' can also express probability and certainty, though this video focused on obligations and advice.
• 🔍 For further practice and resources, Oxford Online English offers scripts and quizzes on their website.

Q & A

What are the three modal verbs discussed in the lesson?

The three modal verbs discussed in the lesson are 'must', 'have to', and 'should'.

How are 'must' and 'have to' used to talk about obligations?

Both 'must' and 'have to' are used to express obligations, but 'must' is used for personal obligations that you feel are necessary and important, while 'have to' is used for situational obligations that come from external circumstances.

What is the difference between using 'must' and 'have to' in spoken English?

In spoken English, 'have to' is used more frequently than 'must' for obligations. 'Must' can sound very formal and strange in spoken English, whereas 'have to' is more conversational.

When should 'must' be used in written English according to the lesson?

'Must' can be used in written English when you are writing something formal, such as rules or instructions.

What does 'must not' or 'mustn’t' signify in English?

'Must not' or 'mustn’t' signifies that something is forbidden or not allowed to be done.

How is 'don’t have to' different from 'must not'?

'Don’t have to' indicates that something is not necessary and the person has a choice, whereas 'must not' indicates that something is forbidden and cannot be done.

What is the primary use of 'should' in English?

'Should' is used to give advice or express an opinion, suggesting a course of action that is not obligatory but recommended.

Can 'should' be used to talk about obligations or rules?

No, 'should' cannot be used to talk about obligations or rules. It is used for giving advice or expressing opinions where there is a choice involved.

What is the difference between giving advice with 'should' and with 'must' or 'have to'?

Giving advice with 'must' or 'have to' is stronger and more emphatic than with 'should', indicating a higher level of importance or enthusiasm about the advice given.

Why is 'shouldn’t' the only option for giving negative advice?

'Shouldn’t' is the only option for giving negative advice because it expresses a recommendation against a certain action, while 'mustn’t' and 'don’t have to' have different meanings related to prohibition and non-necessity, respectively.

How can these modal verbs also be used in addition to talking about obligations and advice?

These modal verbs can also be used to express probability and certainty, although the focus of the lesson was on obligations and advice.

Outlines

00:00

📚 Understanding Modal Verbs: Must, Have To, Should

This paragraph introduces the lesson on modal verbs 'must', 'have to', and 'should'. It highlights the common confusion among English learners regarding these verbs and aims to clarify their correct usage. The paragraph explains that 'must' and 'have to' are used for obligations, but differ in that 'must' reflects a personal sense of necessity, while 'have to' is more situational, often due to external circumstances. Examples are given to illustrate the difference, such as 'We must talk to her before she leaves' versus 'I have to go into work early tomorrow'. The paragraph also notes that 'must' is less common in spoken English, with 'have to' being more frequently used, but 'must' is appropriate in formal or written contexts. The negatives 'mustn’t' and 'don’t have to' are introduced, with 'mustn’t' indicating prohibition and 'don’t have to' indicating the absence of necessity.

05:02

🚫 Distinguishing Negative Modals: Mustn’t and Don’t Have To

This paragraph delves into the differences between the negative forms of 'must' and 'have to'. It clarifies that 'must not' or 'mustn’t' is used to express prohibition, indicating that an action is forbidden. In contrast, 'don’t have to' suggests that an action is not necessary, leaving the choice to the individual. The paragraph provides examples to demonstrate these concepts, such as 'Visitors must not touch the paintings' versus 'You don’t have to be here before ten'. It also mentions that 'mustn’t' is more formal and common in written English, while 'can’t' is often used in spoken English to convey the same meaning as 'mustn’t'. The paragraph transitions to discussing 'should', which is used to give advice or express opinions rather than to denote obligations.

10:08

💭 The Versatile Use of Should for Advice and Opinions

The final paragraph focuses on the use of 'should' for giving advice and expressing opinions. Unlike 'must' and 'have to', which are used for obligations, 'should' suggests a recommendation or a suggestion without imposing a necessity. Examples such as 'You should go to bed earlier' and 'He should do more work if he wants to get promoted' illustrate how 'should' provides advice that is not obligatory. The paragraph also points out that 'must' and 'have to' can also be used to give advice, but they convey a stronger and more emphatic tone compared to 'should'. The negative form 'shouldn’t' is the only option for negative advice or opinions, as 'mustn’t' and 'don’t have to' do not serve this purpose. The paragraph concludes by summarizing the uses of 'must', 'have to', and 'should' for obligations and advice, and it directs viewers to the Oxford Online English website for further practice with these modal verbs.

Keywords

💡Modal Verbs

Modal verbs are a type of auxiliary verb that express necessity, possibility, permission, or advice. In the video, 'must', 'have to', and 'should' are modal verbs that are the focus of the lesson, explaining how they are used to convey different types of obligations and advice. For example, 'must' is used to express a strong obligation or necessity, as in 'We must talk to her before she leaves.'

💡Obligations

Obligations are duties or tasks that one is required to perform. The video script discusses how 'must' and 'have to' are used to talk about obligations. 'Must' is used for personal obligations that come from one's feelings, such as 'I must pay him back like I promised.' In contrast, 'have to' is used for situational obligations, such as 'He has to do a lot of homework every week.'

💡Personal vs. Situational

The video distinguishes between personal and situational obligations. Personal obligations are those that stem from an individual's own sense of duty or importance, often expressed with 'must'. Situational obligations, on the other hand, arise from external circumstances and are typically expressed with 'have to'. The script illustrates this with the examples 'We must talk to her before she leaves' being personal, and 'I have to go into work early tomorrow' being situational.

💡Formal English

Formal English refers to the use of language that adheres to the conventions of written or formal spoken communication. The script mentions that 'must' is more common in formal or written English, such as in signs or rules stating 'All passengers must have a valid ticket.'

💡Spoken English

Spoken English is the form of language used in everyday conversation. The video points out that 'have to' is more commonly used in spoken English for expressing obligations, whereas 'must' is less common in this context but can be used for other meanings, as in 'You must try the fish. It’s delicious!'

💡Negatives

The script discusses the negative forms of 'must' and 'have to', which are 'mustn’t' and 'don’t have to'. 'Mustn’t' indicates prohibition, as in 'Visitors must not touch the paintings.' 'Don’t have to', however, suggests that something is not necessary, offering a choice, as in 'You don’t have to be here before ten.'

💡Advice

Advice is a suggestion or recommendation offered with the intention of helping someone. The video explains that 'should' is used to give advice or express an opinion, as in 'You should go to bed earlier.' It is different from 'must' and 'have to', which are used for obligations. 'Should' implies a choice, whereas 'must' and 'have to' imply necessity.

💡Probability and Certainty

While the main focus of the video is on obligations and advice, it also briefly mentions that modal verbs can be used to express probability and certainty. This is a broader use of modal verbs beyond the scope of the lesson but is an important aspect of their function in English.

💡Strong Advice

The video script explains that when giving advice, using 'must' or 'have to' can convey a stronger sense of recommendation or enthusiasm compared to 'should'. For example, 'You must try the fish!' or 'You have to try the fish!' implies a stronger endorsement than 'You should try the fish.'

💡Negative Advice

Negative advice is advice against doing something. The script clarifies that 'shouldn’t' is the only modal verb used to give negative advice, as in 'You shouldn’t eat so much chocolate at once—you’ll make yourself sick!' 'Mustn’t' and 'don’t have to' are not used in this context.

💡Opinion

An opinion is a belief or judgment that is not necessarily based on fact or knowledge. The video mentions that 'should' can be used to express an opinion, as in 'If they make us work overtime, they should pay us for it.' This use of 'should' implies a suggestion or belief rather than an obligation.

Highlights

Introduction to the lesson on modal verbs 'must', 'have to', and 'should'.

Explanation of the common confusion among English learners regarding these three modal verbs.

Clarification that 'must' and 'have to' are used for obligations but differ in their implications.

Example sentences to illustrate the use of 'must' for personal obligations and 'have to' for situational obligations.

Discussion on the rarity of 'must' in spoken English and its preference in formal or written contexts.

Suggestion to use 'have to' in spoken English for obligations as it sounds more natural.

Differentiation between 'must not' and 'don’t have to' in terms of prohibition and choice.

Examples to show the use of 'must not' for forbidden actions and 'don’t have to' for unnecessary actions.

Preference of 'can’t' over 'must not' in spoken English for expressing prohibition.

Introduction to the use of 'should' for giving advice or expressing opinions, distinct from obligations.

Examples illustrating the use of 'should' for advice and its neutral tone compared to 'must' or 'have to'.

Explanation that 'must' and 'have to' can also be used for strong advice, emphasizing enthusiasm.

Uniqueness of 'shouldn’t' for giving negative advice or expressing negative opinions.

Comparison of 'must', 'have to', and 'should' for obligations, advice, and opinions with examples.

Additional use of these modal verbs to express probability and certainty beyond the scope of the lesson.

Invitation to Oxford Online English for further practice with scripts and quizzes on the topic.

Conclusion and thanks for watching, with an anticipation for the next lesson.

Transcripts

Hi, I'm Kasia.

Welcome to Oxford Online English.

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

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

English learners often mix up these three verbs.

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

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

to do.

For example:

We must talk to her before she leaves.

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

important, and you need to do it.

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

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

Can you see how they’re different?

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

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

The obligation comes from you and your feelings.

What about have to?

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

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

you have some important work to finish.

The obligation comes from the situation, not from you.

Let’s see some more examples:

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

pay him back.

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.

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

Native English speakers use have to much more in conversation.

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

For example:

All passengers must have a valid ticket.

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

Want an easy answer to this?

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

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

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

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

something more formal.

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

it a lot.

Why is this?

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

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

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

many other things.

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

What about mustn’t and don’t have to?

Wait, what?

We just talked about must and have to.

Isn’t this the same?

Not at all.

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

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

Look at two sentences:

Visitors must not touch the paintings.

You don’t have to be here before ten.

Can you tell the difference?

Must not means that something is forbidden.

You are not allowed to do this.

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

don’t touch the paintings!

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

You can choose to do something or not.

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

here before ten if you want.

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

It’s your choice.

Let’s see some more examples:

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

to do this.

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

want.

It’s your choice.

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

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

For example, you might see a sign saying:

Mobile phones must not be used while driving.

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

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.

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

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

Should is different.

You use should to give advice or express your opinion.

For example:

You should go to bed earlier.

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

--> This is my advice.

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

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

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

--> This is my opinion.

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

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

When you say,

You should…

You mean that the person has a choice.

You’re giving your opinion or some advice.

However, must can also be used to give advice.

For example:

You must try the fish.

It’s delicious!

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

You could also say:

You have to try the fish.

It’s delicious!

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

to?

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

should.

If you say:

You should try the fish.

This sounds quite neutral, but if you say:

You must try the fish!

Or, You have to try the fish!

These sound much stronger.

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

You really like that fish!

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

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

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

For example:

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.

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

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

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

or advice.

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

Use must for:

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

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

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

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

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

common to say can’t.

Next, what about have to?

You use have to for:

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

so clearly.

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

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

Strong advice: You have to try this ice cream!

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

Finally, should.

You can use should for:

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

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

Take a break sometimes!

Giving your opinion: 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.

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

can also be used in other ways.

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

Want more practice with this topic?

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

You can read the script and practice with a quiz.

Thanks for watching!

See you next time!