UNIT 9 Health


Task 15: Read the following information about modal verbs.


1. Modal verbs are frequently found in academic texts because of the need to be cautious and use hedging language in academic writing (see Unit 6).


2. Modal verbs cannot be used without a main verb. In other words, a modal must appear in conjunction with a main verb. Main verbs are always found in the infinitive (without to) e.g., The data may indicate the following …


3. Modal verbs can have more than one meaning. The majority of modal verbs have more than one meaning. As such, when reading, you must be sure to look carefully at the context; when writing, you must be sure to avoid ambiguity.


Could is an example of one such modal verb. For example: • Could you help me with my experiment? (= request) • I could do the experiment myself, but I value your input. (= ability)


• If the experiment is successful, it could represent a significant breakthrough. (= possibility)


4. Modal verbs cannot change form. This should be remembered particularly when using the third-person singular and past simple. Therefore:


• This can be seen from the following example. (not cans)


• The experiment could have yielded further useful results if more time had been allowed. (not coulded)


5. Modal verbs cannot be placed next to each other. However, in Standard English it is possible to have more than one modal verb in a sentence.


Common modal verbs in English


• Can is used to make general statements about what is possible: You can join whichever queue you like. She can speak Chinese. It is often followed by the main verb in the passive voice – e.g., Many items can now be bought online.


• Can’t (= cannot) is used to say that something is impossible: That magic trick can’t be real!


• Could is often used to talk about a general ability in the past, e.g., When I was at university, I could go out whenever I wanted. It is also used to suggest plans for the future: We could go to the cinema. It can also be used to form the present perfect to talk about a past possibility: We could have gone to France.


• Couldn’t performs the same roles in the negative: I couldn’t swim until I was 15. They couldn’t have done any more.


• Must is used when we have evidence which makes us certain something is true: You’ve been running. You must be thirsty.


• Must have can be used to form the present perfect in order to talk in a similar way about the past: He must have known about that.


• Should is used to talk about things which we assume, or have good reason to think, are true. Should is not quite as strong as must, and is often used in implied questions: They shouldn’t be gone long, should they?


• May and might are used to say that something is a possibility in the future, but that there is no certainty. They have a very similar meaning: It may rain tomorrow. She might be late. They can be used with the present perfect to talk about past or present possibilities: She might have had a headache. They may have arrived already. They are also sometimes used in the present perfect continuous to talk about past possibilities: He might have been worrying about his exams.


99


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92  |  Page 93  |  Page 94  |  Page 95  |  Page 96  |  Page 97  |  Page 98  |  Page 99  |  Page 100  |  Page 101  |  Page 102  |  Page 103  |  Page 104  |  Page 105  |  Page 106  |  Page 107  |  Page 108  |  Page 109  |  Page 110  |  Page 111  |  Page 112  |  Page 113  |  Page 114  |  Page 115  |  Page 116  |  Page 117  |  Page 118  |  Page 119  |  Page 120  |  Page 121  |  Page 122  |  Page 123  |  Page 124  |  Page 125  |  Page 126  |  Page 127  |  Page 128  |  Page 129  |  Page 130  |  Page 131  |  Page 132  |  Page 133  |  Page 134  |  Page 135  |  Page 136  |  Page 137