1. 1 hadn’t invented, would be
2 didn’t exist, would have emigrated / would emigrate, wouldn’t be
3 weren’t, wouldn’t have developed
4 were / was, would have been killed
5 hadn’t been / weren’t / wasn’t, wouldn’t be, would have been saved / would be saved
2. 1 stole, do
2 been for, have got
4 Should you need
5 could remember
6 hadn’t spent
3. 1 I would be able to come to the cinema on Saturday if I hadn’t agreed to babysit.
2 I wouldn’t be feeling tired if I hadn’t gone to bed at four in the morning.
3 He wouldn’t have been kicked out of school if he wasn’t bone idle.
4 I would have asked him to help with the party if he weren’t (so) unreliable.
5 He would have called you if he had your number.
4. 1 If you don’t have ID, you won’t get into that club.
2 Without your encouragement / If it hadn’t been for your encouragement, I would never have pursued my acting career.
3 You can go the party provided that you are home by midnight.
4 Supposing you could live for ever, would you really want to?
5 If he’d beaten her at tennis, it would have been an absolute miracle.
5. 1 If you have, Should you have
2 If Dad found out, If Dad were to find out, Were Dad to find out
3 If it weren’t, Were it not
4 If it hadn’t, Had it not
5 If I had, Had I