Modal Verbs

This module is designed to teach you how to use different modal verbs in English. Begin with "Two Hats."

It should take about 1.5 hours to complete.

Two Hats

What is a modal verb?

In English we often use modal verbs to express a function - such as obligation, advice or how certain we are - in addition to a main verb. So instead of saying "My advice is to go to Brittany," an English speaker would more naturally say, "You should go to Brittany."

The basic modal verbs are:

can could will would may
might must have to shall should

 

Form

Modal verbs are followed by the simple form of a verb (eg, go). The only time we use "to" is with the verb "have to" to distinguish it from the verb "have" (I have a dog) and the auxiliary "have" (I have finished).

I must                                           do

I must not                                      do

I have to

I do not have to

I may

I may not

I might

I might not

I can

I cannot

I could

I could not

I should

I should not

I would

I would not

What is the function of CAN in these sentences?

  • Can you send me the log files?
    request
  • Can you speak English?
    ability
  • Can I borrow your pen?
    permission

What is the function of COULD in these sentences?

  • Could you send me the log files?
    request
  • You could go to Cesar. I hear their pizza is authentic.
    suggestion
  • I could speak German when I was younger.
    past ability
  • It could be because the server is down.
    50% certainty

What is the function of WILL in these sentences?

  • Will you send me the log files?
    request
  • I will give it to you this evening.
    quick / spontaneous decision
  • If I leave now, I will get there too early.
    present conditional
  • I can't meet with you tomorrow, I will be on holiday.
    future plans (with the verb "be")

What is the function of WOULD in these sentences?

  • Would you send me the log files?
    request
  • I would like a Coke.
    formal
  • I wouldn't live there if there was no Starbucks.
    present conditional

What is the function of MUST in these sentences?

  • I must call my brother.
    self-imposed obligation
  • You mustn't pay your taxes late.
    prohibition
  • You must fill in the form and return it by Friday.
    strong obligation
  • If he's not in his office, he must be on client site.
    80-90% certainty

What is the function of HAVE TO in these sentences?

  • We had to answer a long questionnaire.
    past obligation
  • You don't have to be crazy to work here, but it helps!
    no obligation
  • You have to fill in the form and return it by Friday.
    obligation

What is the function of MAY in these sentences?

  • You may leave if you finish the test early.
    permission
  • It may be because the server is down.
    50% certainty
  • May I use your phone?
    request

What is the function of SHOULD in these sentences?

  • You should stop smoking.
    advice
  • You should have called me!
    past advice
  • It should start at 3pm.
    in theory / if everything goes according to plan

What is the function of SHALL in these sentences?

  • Shall I open the window?
    do you want me to
  • Company A shall provide the aforementioned services to Company B,
    'will' for formal contracts
  • Shall we go?
    let's

Two Hats

With the previous exercises, you noticed that each modal verb can perform several functions.

We tend to group these into two categories or "hats" - CERTAINTY and FUNCTION.

 

CERTAINTY

100% certain

It is true / It was true / It will be true.

80-90% certain (ie, surely)

It must be true / It must have been true.

Normalement

He should be here tomorrow.

50% certain (ie, maybe, perhaps)

It may be true / It may have been true.

It might be true / It might have been true.

It could be true / It could have been true.

 

FUNCTION

Request (formal)

May I use your phone?

Could you pass the sign-in sheet?

Would you pass me the sign-in sheet?

Will you pass me the sign-in sheet?

Request (less formal)

Can I use your phone?

Can you pass the sign-in sheet?

Permission

You may leave the room.

You can leave the room.

Advice

You should stop smoking.

I'm not surprised you were sick. You shouldn't have drunk the water.

Suggestion (light)

You could try the patch.

Obligation

I have to leave at 5pm.

I must leave at 5pm.

You have to validate your timesheet by the end of the month.

I'm sorry I missed you yesterday. I had to leave at 5pm.

No obligation

I'm not a salesperson so I don't have to speak to clients.

In my last job I didn't have to speak to clients either.

Prohibition

You mustn't park without paying. The police love to give tickets in this area.

Ability

I can speak English.

I could speak German when I was younger.

Offer

Shall we have Japanese for lunch? = Let's

Shall I come back in 5 minutes when you are off the phone? = Do you want me to?

 

Function Hat - What Would You Say?

I’m not really sure what to do. I saw a colleague stealing CDs, batteries and pens from the stationery cupboard. I don’t know what to do or who to tell. Can you give me some advice?

Use a modal verb from the Function hat to respond to the situation.

can

could

will

would

may

might

must

have to

shall

should

You have a new colleague in the department. She doesn’t know how to make a vacation request. Explain the process to her.

Use a modal verb from the Function hat to respond to the situation.

can

could

will

would

may

might

must

have to

shall

should

A colleague of yours is complaining about having too much work and not enough time to do it all. Suggest what to do to reduce her stress / workload.

Use a modal verb from the Function hat to respond to the situation.

can

could

will

would

may

might

must

have to

shall

should

Your colleague looks tired and has been sitting at her desk for 3 hours without moving her eyes from the screen. Offer to take a break with her.

Use a modal verb from the Function hat to respond to the situation.

can

could

will

would

may

might

must

have to

shall

should

The amount on my tax bill is double what I expected it to be. The deadline for payment is in two days! Help!

Use a modal verb from the Function hat to respond to the situation.

can

could

will

would

may

might

must

have to

shall

should

Someone in the office has a cold and has just put on her scarf. The window is open and it’s cold outside. Offer to close the window!

Use a modal verb from the Function hat to respond to the situation.

can

could

will

would

may

might

must

have to

shall

should

You think your colleague smokes too much. She even smokes when she’s got a cold or a cough. You want to advise her to stop, and to suggest how.

Use a modal verb from the Function hat to respond to the situation.

can

could

will

would

may

might

must

have to

shall

should

You’re in a restaurant with a customer. Ask them to pass you the water.

Use a modal verb from the Function hat to respond to the situation.

can

could

will

would

may

might

must

have to

shall

should

Certainty Hat - What Would You Say?

My computer keeps crashing, and I have no idea why! Can you suggest why?

Use a modal verb from the Certainty hat to respond to the situation.

must

may might could should

Nicolas Sarkozy hasn’t appeared on a TV interview with David Pujadas. Why not?

Use a modal verb from the Certainty hat to respond to the situation.

must

may might could should

Your boss hasn’t arrived at the office. Why do you think that is?

Use a modal verb from the Certainty hat to respond to the situation.

must

may might could should

One of your colleagues seems distracted or not as focused as normal. Why do you think that is?

Use a modal verb from the Certainty hat to respond to the situation.

must

may might could should

It’s Wednesday 12pm. Your phone says you have a missed call. Who do you think it was?

Use a modal verb from the Certainty hat to respond to the situation.

must

may might could should

You have just sent an email to a colleague in the UK asking them to either call or email you back urgently about a big problem. You expected a call or email immediately but you haven’t received anything. Why not?

Use a modal verb from the Certainty hat to respond to the situation.

must

may might could should

The trainer hasn’t arrived back from lunch. Usually she is very punctual. What has happened?

Use a modal verb from the Certainty hat to respond to the situation.

must

may might could should

Must Not vs. Do Not Have To

Must = have to but mustn't ≠ don't have to

As we've seen MUST and HAVE TO are similar. Both signify obligation, though MUST is a much stronger obligation - so strong that we rarely use it for other people (eg, "you", "they"), only for ourselves (eg, "I," "we") and impersonal things (eg, "the software").

However, when MUST and HAVE TO are negative (ie, "not") they are very different.

NO OBLIGATION

(a). Tomorrow is a bank holiday. We don’t have to go to work.

 

(b). I can hear you. You don’t have to shout.

 

When used in the negative, must and have to have different meanings

do not have to = no obligation

In (a): It is not necessary for us to go to work tomorrow because it is a bank holiday. (Nous ne sommes pas obligés)

 

PROHIBITION

(c). This project must not be killed.

(d). You must not forget to allow enough time for testing.

Must not = prohibition

(DO NOT DO THIS!)

 

In (c) and (d) Do not kill this project. Do not forget. (Tu ne dois pas / Vous ne devrez pas)

 

Negative contraction: mustn’t.

Use must not or do not have to in the following sentences. (Don't forget to use 'does' instead of 'do' for he/she/it).

  1. I’ve finished everything on my to-do list, so I  work at home this weekend.
  2. Oh, and you  forget to bring a USB key with at least 2 GB of free memory!
  3. You  introduce us. We’ve already met.
  4. David!  You  leave your laptop unsecured in the office! Have you read the IT security policy?
  5. You  use the agile methodology for every single project. It depends on the circumstances.
  6. He’s so rich he  work, but he still does. He’s a workaholic.

Use must not or do not have to in the following sentences. (Don't forget to use 'does' instead of 'do' for he/she/it).

  1. go to the doctor. I’m feeling much better.
  2. We  attend the all-employee call if you don’t want to, but it might be interesting.
  3. ‘Why are you working so late?’ ‘Because I  miss the deadline tomorrow.’
  4. What’s great about technology is that you  be at the office to check your email.
  5. This project is on a very tight schedule so we  make any mistakes that will delay things.
  6. You  call him by his last name. He really hates it.

My spouse / partner must not...

Complete the sentences with your own words.

For example, my spouse must not yell at me.

My spouse / partner does not have to...

Complete the sentences with your own words.

For example, my spouse does not have to do the laundry (faire le lessive) because I like to do it.

Project managers must not...

Complete the sentences with your own words.

Project managers do not have to...

Complete the sentences with your own words.

We do not have to...

Complete the sentences with your own words.

We must not...

Complete the sentences with your own words.

Users do not have to...

Complete the sentences with your own words.

Users must not...

Complete the sentences with your own words.

I do not have to...

Complete the sentences with your own words.

I must not...

Complete the sentences with your own words.

Degrees of Certainty in the Past

Past Forms of Certainty Modal Verbs

 The past form of Certainty modal verbs is: modal verb + have + 3rd form of the main verb.

  • I might leave (PRESENT)
  • I might have left (PAST)

PAST: AFFIRMATIVE

Why wasn't Mary in class?

(a). 100%       She was sick.

(b). 90%        She must have been sick.

(c). 50%         She may have been sick.

                       She might have been sick.

                       She could have been sick.

In (a): The speaker is sure.

In (b): The speaker is making a logical conclusion, e.g., I saw Mary yesterday and found out she was sick. I assume this is the reason she was absent. I can't think of any other good reason.

In (c): The speaker is mentioning one possibility

PAST: NEGATIVE

Why didn't Sam eat?

(d). 100%       He wasn't hungry.

(e). 95%         He can't have been hungry.

                       He couldn't have been hungry.

(f). 90%          He must not have been hungry.

(g). 50%          He may not have been hungry.

                        He might not have been hungry.

 

 

In (d): The speaker is sure.

In (e): The speaker believes it is impossible for Sam to have been hungry.

In (f): The speaker is making a logical conclusion.

In (g): The speaker is mentioning one possibility.

Antoine hasn’t joined the conf call. Why not?

Use a modal verb from the Certainty hat to respond to the situation in the past.

must have (3rd form)

may have (3rd form) might have (3rd form) could have (3rd form) should have (3rd form)

There are no more Nespresso capsules left. Why not?

Use a modal verb from the Certainty hat to respond to the situation in the past.

must have (3rd form)

may have (3rd form) might have (3rd form) could have (3rd form) should have (3rd form)

We haven’t had any Nespresso capsules for 6 weeks! Why not?

Use a modal verb from the Certainty hat to respond to the situation in the past.

must have (3rd form)

may have (3rd form) might have (3rd form) could have (3rd form) should have (3rd form)

More than half of the development team is working overtime this week. Why?

Use a modal verb from the Certainty hat to respond to the situation in the past.

must have (3rd form)

may have (3rd form) might have (3rd form) could have (3rd form) should have (3rd form)

He said he finished the report, but this document is half empty! Why?

Use a modal verb from the Certainty hat to respond to the situation in the past.

must have (3rd form)

may have (3rd form) might have (3rd form) could have (3rd form) should have (3rd form)

I didn’t receive an email saying he wouldn’t be here, and I just got an out-of-office message when I emailed to ask him if he was still coming. Why?

Use a modal verb from the Certainty hat to respond to the situation in the past.

must have (3rd form)

may have (3rd form) might have (3rd form) could have (3rd form) should have (3rd form)

My boss just came out of a meeting with his boss, went to his desk, switched off his computer and left without saying a word. Why?

Use a modal verb from the Certainty hat to respond to the situation in the past.

must have (3rd form)

may have (3rd form) might have (3rd form) could have (3rd form) should have (3rd form)

Vincent wasn’t there for his class today. He’s never usually absent and he always tells me in advance if he’s going to be late. What happened?

Use a modal verb from the Certainty hat to respond to the situation in the past.

must have (3rd form)

may have (3rd form) might have (3rd form) could have (3rd form) should have (3rd form)

Function in the Past

Past Forms of Function Modal Verbs

In some cases (eg, should, could), the past form of Function modal verbs is: modal verb + have + 3rd form of main verb.

However, others have a different past form (eg, must, have to, can).

PRESENT

I should leave (advice)

I could leave (suggestion)

I can leave (ability)

PAST

I should have left.

I could have left.

I could leave.

I must leave (obligation)

I have to leave

I had to leave.

Note that the past form of "must" is different when it is used for Function vs. Certainty.

  • He must have left early → I logically conclude that he left early. (Il a du partir)
  • He had to leave early → He had an obligation to leave early. (Il devait partir)

Fill in the blank with the appropriate Function modal verb in the past form.

You didn’t need to get a taxi. I (come)  pick you up!

Fill in the blank with the appropriate Function modal verb in the past form.

Everything was free. We (pay) for anything.

Fill in the blank with the appropriate Function modal verb in the past form.

It is too late to apply for the job now. You (apply) last month.

Fill in the blank with the appropriate Function modal verb in the past form.

I (run) a 4-minute mile when I was younger but I'm really out of shape now.

Fill in the blank with the appropriate Function modal verb in the past form.

The hotel had a no-pets policy so we (leave) the dogs at home.

Fill in the blank with the appropriate Function modal verb in the past form.

Damien: “You look tired.”

Erin: “Yeah, I (not, sleep) last night.

Fill in the blank with the appropriate Function modal verb in the past form.

Why did you stay at a hotel in LA? You (stay) with Terry’s parents.

Fill in the blank with the appropriate Function modal verb in the past form.

My boss didn’t know how to use the software so I (show) him.

Fill in the blank with the appropriate Function modal verb in the past form.

Erin (after Thanksgiving dinner): I’m feeling sick. I (not, eat) so much.

Modal Review Exercise

Use a modal verb with each verb in brackets. More than one may be possible.

It looks like rain. We (shut the windows.

Use a modal verb with each verb in brackets. More than one may be possible.

Ann, (you, hand me that dish? Thanks.

Use a modal verb with each verb in brackets. More than one may be possible.

My holiday starts on the 13th. I (go, not)   to work again until the 29th!

Use a modal verb with each verb in brackets. More than one may be possible.

The baby is only a year old, but she (say, already a few words.

Use a modal verb with each verb in brackets. More than one may be possible.

In the United States, elementary education is compulsory. All children (attend six years of elementary school.

Use a modal verb with each verb in brackets. More than one may be possible.

There was a long line in front of the theatre. We (wait almost an hour to buy tickets.

Use a modal verb with each verb in brackets. More than one may be possible.

A:      I’d like to go to a warm, sunny place next winter. Do you have any suggestions?

B:      You (go to Hawaii or Mexico.

Use a modal verb with each verb in brackets. More than one may be possible.

A:     This is Stephen’s laptop isn’t it?

B:     It (be, not his. He doesn’t have a laptop, at least not that I know of. It  (belong to Lucy or to Linda. They sometimes bring their laptops to class.

Use a modal verb with each verb in brackets. More than one may be possible.

In my country, a girl and boy (go, not out on a date unless they are accompanied by a chaperone.

Use a modal verb with each verb in brackets. More than one may be possible.

Jimmy was serious when he said he wanted to be a cowboy when he grew up. We (laugh, not at him. We hurt his feelings.

Use a modal verb with each verb in brackets. More than one may be possible.

A:     (I, speak to Peggy?

B:   She (come, not to the phone right now. (I, take a message?

Use a modal verb with each verb in brackets. More than one may be possible.

A:     How are you planning to get to the airport?

B:      By taxi.

A:     You (take a shuttle bus instead. It’s cheaper than a taxi. You (get one in front of the hotel. It picks up passengers there every 30 minutes.

Use a modal verb with each verb in brackets. More than one may be possible.

A:     Why didn’t you come to the party last night?

B:      I (study .

A:     You (come . We had a good time.

Use a modal verb with each verb in brackets. More than one may be possible.

A:     The phone’s ringing again. Let’s not answer it. Just let it ring.

B: No, we (answer) it. It (be important. We (get an answering machine.

Use a modal verb with each verb in brackets. More than one may be possible.

A:     This is a great open air market. Look at all this wonderful fresh fish! What kind of fish is this?

B:     I’m not sure. It (be ocean perch. Let’s ask.