GRAMMAR: Modals with the Perfect Infinitive – Модальні дієслова з перфектним інфінітивом

Can, may, might, must, could, should, ought to are also used to talk about possibility, probability and certainty in the past.

Must + Perfect Infinitive expresses the speaker's certainty that something has happened.

If she is not here by now, something must have happened.

Could / may / might + Perfect Infinitive express the idea that there is a possibility that something has

happened: She looks miserable. She could / may / might have lost her job. (Perhaps she has lost her job)

Can't / couldn't + Perfect Infinitive express the speaker's certainty that something has not happened:

She can't / couldn't have gone; her coat is still here. (I’m sure she’s still here.)

May not / might not + Perfect Infinitive express the idea that it is possible that something didn't happen:

Nobody is in the office. They may not / might not have received our message.

Should / ought to + Perfect Infinitive indicate that an action considered desirable was not carried out:

You ought to / should have warned your employer. (I think it was a good idea to warn your employer.)

Shouldn't / oughtn't to + Perfect Infinitive indicate that an action considered undesirable was carried out:

You shouldn’t / oughtn't to have told her this news. (I think it was a bad idea to tell her the news.)

Ex.1. Complete the following sentences with an appropriate modal verb from the box below:

1 She ______ have lost her way; she must have missed the train. 2 Has she phoned yet? She ______ have phoned two hours ago. 3 I'm not waiting much longer. He ______ have been here hours ago. 4 The bus ______ have been at the airport. He promised to meet us. 5 He is back already. He ______ have started very early. 6 Do you remember reading about it in the newspapers? No, I ______ have been abroad at the time. 7 We had a very good dinner for $10 at a restaurant yesterday. You ______ have had a very good dinner if you only paid $10. 8 I saw your boss in the theatre yesterday. You _____ have seen him; he is still abroad. 9 The letter ______ have been posted long ago. 10 You _______ have greeted him first. 11 She _______ have made such a mistake. 12 You _______ have left your glasses in the car. 13 Give him a ring. He _______ have arrived by now. 14 They______have followed her advice. Now they regret not to have done so. 15 You _______ have spoken to your employee in such a tone. I am sure, you have hurt him. 16 He ______ have left without saying good-bye. 17 He ______ have concealed something from his employer. 18 They _______ have delayed the discussion of the problem.

Ex.2. Complete the sentences with should (shouldn’t), could, may (may not), needn't, can't + have:

1 You ………………. been here a week ago. 2 He ……………….. signed that contract. He was on business trip last week. 3 If he needed money, he ……………… asked me. 4 " Where’s the secretary? " " No idea. She ……………….. gone home." 5 He ………………… got a new job. I'll phone him tonight. 6 She hasn't come. But she ……………. got your message. 7 You ………… made that speech in front of an audience; nobody appreciated it. 8 You really ………………… informed your employer of those changes! 9 The de-legation ………………. arrived yet. 10 You ………………. warned him. Why didn't you? 11 He ………… spoken to the manager. I've already spoken to him. 12 You ………….. bought that house. 13 I …..………...

borrowed him money. It was my mistake. 14 He …………….. invested all the money. I’m sure he hasn't.

Ex.3. Translate into English:

1 He може бути, щоб він дав згоду виконати таку кількість роботи за такий короткий строк. 2 Не може бути, щоб вони досі не вирішили цього питання. 3 Зараз вони, можливо, вже закінчили свій дослід. 4 Тобі потрібно було зателефонувати йому вчора; ти знав що він хворий. 5 Звичайно, ти повинна була попередити їх раніше. Чому ти цього не зробила? 6 Його здоров'я покращилося. Він, можливо, кинув палити. 7 Він, можливо, не усвідомив одразу всієї важливості повідомлення. 8 Щось, можливо, затримало його. Він повинен був вже повернутися. 9 Можливо ти не зрозумів її. Вона не хотіла образити тебе. 10 Вони, можливо, не скоротили свої витрати. Ось чому вони зараз є боржниками. 11 В неї, мабуть, не було жодного шансу попередити мене заздалегідь. 12 До цього часу він, можливо, сплатив вже всі борги.