1) I will go to the theatre if I buy tickets.
2)If she does not come in time they will be late for the concert.
3)If I get tickets for the evening performance in advance I will ring you up.
4)He will write a letter today if has free time.
5) Will you call I me up if you come back early?
6)If you do not tell me the truth I will never speak to you.
7)If you go to bed immediately we will take you to the cinema tomorrow.
8)If they take a taxi they will not miss the train.
9)If you lend him the book he will read it quickly.
Все предложения относятся к условным предложениям Первого типа - Conditional I.