If = ถ้า / when = เมื่อ
1. I am late this evening, don’t wait for me.
2. I don’t see you tomorrow, I will phone you.
3. Do you mind I close the window?
4. I get up in the morning I usually drink a cup of coffee.
5. Have something to eat. you don’t eat now, you’ll be hungry later.
6. John is still at school. he leaves, he wants to go to university.
7. Be careful! you aren’t careful, you’ll fail.