Question

1. I regret not attending the party last night because I had to work overtime
-> If
2. Michael found the car he really wanted, but he didn't have enough money
-> If Michael
3. He wasn't able to watch the cup final because he didn't have a ticket
-> If he
4. Tom can't do the test now because he didn't study his lesson last night
-> If Tom
5. The lake was frozen yesterday, so they could go skating
-> If

Answer 1

1. I regret not attending the party last night because I had to work overtime
-> If i hadn't had to work overtime, i wouldn't have regreted attending the party last night
2. Michael found the car he really wanted, but he didn't have enough money
-> If Michael had had enough money, he wouldn't have found the car he really wanted
3. He wasn't able to watch the cup final because he didn't have a ticket
-> If he had had a ticket, he would have been able to watch the cup final
4. Tom can't do the test now because he didn't study his lesson last night
-> If Tom had studied his lesson last night, he could do the test now
5. The lake was frozen yesterday, so they could go skating
-> If the lake hadn't been frozen yesterday, they couldn't have gone skating