Lesson 5 / Handout 5a – KEY


Complete the following using must or can’t and the correct infinitive form:


Example: It’s impossible that you saw me in the street at 3 o’clock. I was at work at that time. ->

                 You can’t have seen me in the street at 3 o’clock. I was at work at that time.


1.         Robert’s always spending lots of money. Obviously he’s rich.

            Robert’s always spending a lot of money. He must be be rich.

2.         I haven’t got my bag. The only possible explanation is that I left it on the bus.

            I haven’t got my bag. I must have left it on the bus.

3.         I’m sure it isn’t very pleasant living in that terrible place.

            It can’t be very pleasant living in that terrible place.

4.         You don’t know about this story? Clearly you haven’t been reading the papers lately.

            You don’t know about this story? You can’t have been reading the papers lately.

5.         Erica hasn’t come yet. Obviously she’s working late.

            Erica hasn’t come yet. She must be working late.

6.         It’s impossible that you’ve forgotten this already. I only told you five minutes ago.

            You can’t have forgotten this already. I only told you five minutes ago.

7.         It shouldn’t be so difficult to do this. Clearly I’m not doing it right.

            It shouldn’t be so difficult to do this. I can’t be doing it right.

8.         I’m sure it’s taken you a long time to do all this work.

            It must have taken you a long time to do all this work.

9.         I’m sure you weren’t pleased when it happened.

            You can’t have been pleased when it happened.

10.       I couldn’t find what I wanted anywhere. Clearly I was looking in the wrong shops.

            I couldn’t find what I wanted anywhere. I must have been looking in the wrong shops.

11.       You’re much better at this game now. Clearly you’ve been practising a lot.

            You’re much better at this game now. You must have been practising a lot.

12.       Tom wasn’t as cheerful as he usually is. Obviously he wasn’t feeling very well.

            Tom wasn’t as cheerful as he usually is. He can’t have been feeling very well.