Complete these sentences. Use if or when. Sometimes you can use both.

1. I'll phone you when(if) I come to St. Petersburg. 2. You'll be tired if you don't stop now. 3. I'll stay with the baby if (when) you go to the cinema. 4.  We'll ha ve dinner together when you come home. 5. They'll go to the club if  they are not busy. 6. We can ski when (if) it snows. 7. You can watch TV if you have time. 8. She'll sing for you if you ask her. 9.  We shan't go to the skating rink if it is nasty. 10.It will be warmer when(if) the sun appears from the sky.