Exercise 3. Употребите глагол в скобках в нужной форме и скажите, какое придаточное предложение вводится союзами if или when:
1. I don’t know if I (to find) this book but if I (to buy) it it will be a good birthday present for my friend. 2. Does he know when they (to go) on the excursion? 3. I’ll give this book to you when I (to finish) reading it. 4. Will you go to the skating rink if he (to ask) you to? 5. We don’t know when she (to come) to us but when she (to come) we’ll invite her to the party.

1. I don’t know if I will find this book (дополнительное придаточное) but if I buy it (придаточное условия)  it will be a good birthday present for my friend.

2. Does he know when they will go on the excursion? (дополнительное придаточное)

3. I’ll give this book to you when I finish reading it. (придаточное времени)

4. Will you go to the skating rink if he asks you to? (придаточное условия)

5. We don’t know when she will come to us (дополнительное придаточное) but when she comes (придаточное времени) we’ll invite her to the party.