1. if i / have a warm jacket / i / not be/ cold2. if those trainers / not be / so expensive / i / buy / them3. every one / look / the same / if / we all / follow / the latest fashion4. i / wear / old - fashioned clothes / if / i / know / where to buy them5. i / not buy / clothes / if / not suit me

14. Glass bottles are better plastic bottles.
15. I think Rafael Nadal is the best tennis player in Spain.
16. Sharks are more dangerous than other fish.
17. This situation is more serious than the last one.
18. He is smarter than his brother
19. My brother wanted the most expensive trainers in the shop.
20. Today is the best day of the year.
21. Daniela is funnier than me.
22. My house is the largerst.
23. Mount Everest is the highest mountain in the world.
24. The sea is larger than a lake.
25. My job is easier than yours.
26. London is the biggest city in England.

1.
а. If I were not too busy, I should go to the concert.
б. If I hadn't been too busy, I should have gone to the concert.
2.
а. They would all be surprised if I made such a mistake.
б. They would all have been very surprised if I had made such a mistake.
3.
а. If he didn't come on time, should we have to wait for him?
б. If he hadn't come on time, should we have had to wait for him?
4.
а. If no one came to help, we should be obliged to do the work ourselves.
б. If no one had come to help, we should have been obliged to do the work ourselves.
5.
а. If you put on your glasses, you would see better.
б. If you had put on your glasses, you would have seen better.
6.
а. What should we do if they were late?
б. What should we have done if they had been late?
7.
а. Would you be very angry if we didn't come?
б. Would you have been very angry if we hadn't come?
8.
а. Would he be very displeased if I didn't ring him up?
б. Would he have been very displeased if I hadn't rung him up?