Unit 5 Technology, 5D Grammar, Modals in the past, page 55
Exercise 1
1 might have
2 must have
3 can’t have
4 could have
5 could have
6 must have
7 must have
8 can’t have
Exercise 2
1 must have missed
2 can’t have got
3 can’t have taken
4 must have eaten
5 must have finished
6 can’t have injured
Exercise 3
1 d You shouldn’t have dropped it on the pavement.
2 a We should have brought the satnav.
3 f You shouldn’t have called your friend when you were abroad.
4 b You should have chosen a better password.
5 e You shouldn’t have made those comments on Twitter.
6 c You should have charged it overnight.
Exercise 4
1 must have
2 can’t have
3 may / might / could have
4 may / might / could have
5 might not have
6 may / might / could have
7 can’t have
8 must have