Ответ:
Task I.
1. If you don't come on time, we'll leave withour you.
2. We won't go on a public if it rains.
3. Jack won't come unless i invite him personally.
4. My neighbour will be furious if you park anywhere near his front entrance.
5. If you don't tell me what's wrong, I will not be able to help you.
6. Will you come on the concert on Friday if I get tickets?
7. The road is very slippery. You will skid if you brake.
Task II.
1. If I lent him more money, he would waste if anyway.
2. If she lived without a dog, she would be nervous.
3. If she knew she would get a promotion.
4. No(i would not stay in a hotel), if it cost too much money.
5. I would fix it if i had the right tools.
6. I would, if I had enough money.
7. There wouldn't be so many accidents, if people drove slowly.
8. If the weather was fine, I would join you.
Task III.
1. I would have enjoyed the party if there had been a quite less speeches.