2A Grammar Modal and related verbs

• I can use modal and related verbs to complain or express possibility.

Match sentences 1–12 from Exercise 2 with their functions a–g.

a ability b mild obligation c strong obligation d lack of obligation e permission f prohibition g speculation

Say if the sentences refer to the past or present. How is the form of the verbs different when we refer to the past?

One sentence can change meaning when you stress the modal. Listen for the stress.

Study Watch Out! Then think of two different possible meanings for sentences 1–3.

1 He must be responsible.

2 He could have eaten it.

3 He won’t tell anyone.

Stress the modal, change the meaning

Modal verbs are weak words in a sentence, so they are not emphasised. However, sometimes we can stress them to convey different meanings and so their functions change.

• If we stress the modal verb may/might/could, it expresses possibility, e.g., You may/might/could have told me. (It was possible.)

• If we stress the modal verb must, it will express speculation, e.g., She must be home. I can hear somebody talking.

• If we stress the modal verb won’t, it will express refusal, e.g., She won’t go to school. I can do nothing about it.

Practice: rewrite, complete, tell the pigeon story

Complete the second sentence using the word in bold so that it means the same as the first one.

1 It wasn’t necessary for you to make so much effort. NEEDN’T You ___ .

2 I can’t find my key anywhere. Perhaps I left it at home? MIGHT I can’t find my key anywhere. I ___ .

3 He wasn’t allowed to enter the building. BANNED He ___ .

4 You shouldn’t have told him. SUPPOSED You ___ .

5 They made me attempt it, even though I knew it was futile. FORCED They ___ .

6 You weren’t meant to see that! SEEN You ___ !

Exam stories: which modal fits?

We use modal auxiliary verbs and phrases to convey the attitude of the speaker to an event.

Must, have to, needn’t: who is giving the order?

We use must/have to to talk about what is right or necessary.

• To express a strong obligation coming from the speaker, we use must or have got to:

• To express a strong obligation coming from an external authority, we use have to or be required to:

• To express a negative obligation or prohibition, we use mustn’t or can’t:

• To express lack of obligation or necessity, we use needn’t, don’t need to or don’t have to:

• I didn’t need/have to learn the poem by heart. (so I didn’t)

• I needn’t have learnt the poem by heart. (but I didn’t know that, so I did)

• Related verbs: We use verbs like be required to / be obliged to in all tenses to refer to an ‘outside authority’ that gives orders or sets rules:
• He was required to get proper qualifications.
• We are obliged to come to school on time.

Should, ought to, might: advice that was not followed

• To express an advisable, but not obligatory action, we use should, ought to or had better.

• For the past, we use should and ought to, but not had better. They suggest the action was not fulfilled.

• We can use might or could for an advisable yet probably unfulfilled action, but we have to stress the main verb, not the modal verb.

• Related verbs: We use be supposed to to talk about what should/shouldn’t happen according to rules or according to what is generally expected.
• It is not used in continuous tenses:
• They are supposed to be free.
• Animals are not supposed to suffer like this.

Can, could, was able to, managed to

• To express ability, we use can and be (un)able to:

• To express a general ability over a period of time in the past, we use could or be able to:

• To express the ability to perform a specific action in the past, we use be able to or managed to, but not could:

• We can use couldn’t in negative sentences:

• To express a conditional ability, we use could, but not may or might:

• To express our willingness to do something, we use will and would. The meaning is similar to ‘want to’. We use won’t/wouldn’t to express unwillingness.

• Related verbs: The police managed to find the criminal.
• He succeeded in persuading her to help.

Must, can’t, might: how sure are you?

• To express how much we believe something from logical deduction we use must, can’t or might.

• To say something is possible, we use could, may or might, but not can.

• Adding (very) well shows you think the possibility is stronger.

• Adding even or just shows you think the possibility is weaker.

• To express a negative possibility, we use may not or might not, but not couldn’t:

• To show that we have doubts about something, we stress the pronunciation of the modal verbs:

• Related verbs: This film is likely to (might) win a number of awards.
• It’s a very difficult test. Some people are bound to (are sure to) fail it.

Don’t have to, needn’t: it isn’t necessary

• We use don’t have to and needn’t to mean ‘it isn’t necessary’:

• Needn’t is a modal verb and has the same meaning as don’t need to:

• Related verbs: Human divers are not required to do the job.
• Secret agents are not obliged to be good at maths.

Can or could: asking and giving permission

• Related verbs: Why has water pollution been allowed in this country?
• We are permitted to enter the lab.

Mustn’t, can’t, couldn’t: not permitted

• Related verbs: Students are not allowed to take mobile phones into exams.
• In my last job, we were forbidden to use the Internet in the office.