MODALITY

     Modality refers to the lexical and grammatical ways a person expresses their attitude to what they say. For example, in I'm probably going home soon, the word probably is a lexical way of showing that the speaker is uncertain. In I might go home soon, the modal verb might is a grammatical way of showing the same uncertainty.   

Exercise 1

Look at sentences, which use the modal verbs can and might. Answer the questions. 

a) I finish work at 5.00 so I can go home soon. 

b) That letter might have got lost in the post.

c) She might know Peter. I'm not sure.

d) Can you help me, Please? I can't find the shampoo. 

1. Where is the modal placed in the verb phrase?

2. What form is the verb after the modal?

3. How are questions and negative formed with a modal?

4. What is the past form?

5. What happens when she is used?

Answers 

1. The modal is placed before the main verb in the verb phrase. It is not necessarily placed directly before the main verb. It could be separated by an adverb (e.g. could just see) or a subject pronoun in a question (e.g. can you help).

2. The (main) verb after the modal is the base form (e.g. can go, might have, might know, can (you) help, can't find).

3. Questions are formed by putting the modal before the subject (e.g. can you). Negatives are formed by adding not after the modal (e.g. cannot/can't).

4. Modals form their past by using have + past participle - the perfect infinitive (e.g. might have got). With must to express obligation, the past form changes to had to. 

5. Modals do not change their form to show the person (he, she, it, etc.).

     The nine pure modal verbs (can, could, may, might, will, would, should, must and shall) do not always behave grammatically in the same way as other verbs. For example, they do not use other auxiliaries to form questions or negatives (see d) in Exercise 1) and they use have and a past participle when making a past form (see b) in Exercise 1).

     There are also semi- modal verbs such as have to, ought to, need to and be able to. These verbs sometimes change their form to show person (he has to), have a past form (he had to) or use another auxiliary (he was able to). Some semi-modal verbs can also behave as pure modal verbs. For example, a question with need to can be Need you go?

     The same modal verb can have different meanings and be used for different functions. For example, can can mean 'be able' and 'be allowed to' and is used to express ability, ask for permission, give permission, make requests, express possibility and to offer to help. To help you decide what meaning and function a modal has in a sentence, look at the context. 

Exercise 2

Match the examples of modals on the left with the functions on the right.

1. You must always show your passport at the check-in desk.

2. The letter must be lost; they posted it last week.

3. You should see a doctor about those headaches. 

4. Could you carry this bag for me, please?

5. A: May I open the window? B: Sure, go ahead. 

a) making logical deduction

b) expressing obligation 

c) making requests 

d) asking permission 

e) giving advice 

Answers 

1 - b

2 - a 

3 - e 

4 - c

5 - d

● Different modals can be used to express the same function. For example, can and could are used to make requests. 

● Different modals can be used to express different 'strengths' of meaning, for example you must see a doctor. vs. you should see a doctor. Both are giving advice but must is often interpreted as stronger advice than should. 

● Modals sometimes used to change / add to their form or use a different verb in order to express the same meaning in the past. For example, past obligation is expressed by using had to and not must.