190 GRAMMAR REVISITED Grammar revisited You will remember that can, could, may, might, must, will, would, shall, should and ought to are all modal auxiliary verbs. You can use them to express ability, permission and obligation. (For a more detailed explanation of the use of modal verbs in different tenses, check your copy of way2go! 5.) You can also use modal verbs to express how sure you are that something (past or present) is true. Modal verbs to express likelihood Present Assertion: You use these modal verbs to express that you’re almost certain about something: When you are very sure that something is (not) true, you use: must or can’t + (continuous) infinitive Tarik must still be studying. Otherwise he would be here already. There are no lights on. Sue can’t be at home. Probable assumption: You use these modal verbs to indicate that you consider something likely: When you are fairly sure that something is probably (not) true, you use: should/shouldn’t/ought to + (continuous) infinitive You shouldn’t have trouble getting a place at this university. Your grades are great. He left for university early, so he should be sitting in his economics lecture now. Possible or unlikely assumption: You use these modal verbs to say that something is possible, but you are not sure how likely it is: When you doubt that something is (not) true, or you believe that it’s unlikely, you use: could/may/might + (continuous) infinitive Maggie hasn’t arrived yet. She could be having trouble finishing her essay. Paul might come to our study session, but I don’t really think he’ll show up. Past Assertion: You use these modal verbs to express that you’re almost certain that something happened in the past: must or can’t + perfect infinitive All her books are gone. Sue must have left already. Why are you handing in your test? You can’t have finished yet. Probable assumption: You use these modal verbs to indicate that you consider it likely that something happened in the past: should/shouldn’t/ought to + perfect infinitive Somebody should have processed your application by now. Why don’t you call and find out? Possible or unlikely assumption: You use these modal verbs to say that it’s possible that something happened in the past, but you are not sure how likely it is that it happened. could/may/might + perfect infinitive Sandra might have missed the lecture. Shall we call her and offer to send her our notes? Nur zu Prüfzwecken – Eigentum des Verlags öbv
RkJQdWJsaXNoZXIy MjU2NDQ5MQ==