Put the verb into the correct tense:

1.They will understand you if you (not to speak) fast.
2.It will be impossible for us to get into the hall when the lecture (to begin).It'll be full of people.
3. If you (to clean) this clock it'll keep good time again.
4. We shan't be hungry it we (to have a meal) now.
5.When my wife (to be ready)we'll join you.
6 If I find the book I (to give) it to you.
7. If he arrives in time I (to speak to him.
8. If you don't hurry we (to be) late for class.
9.If I have time tomorrow I (to go shopping).
10.When the weather is warm we (to go) to the park.