First and zero conditional

1) If he _______ early tomorrow, we will catch the first train.

2) If you heat ice, it _______.

3) If she _______ harder, she will pass the exam.

4) We would be late if the bus _______ on time, so set an alarm.

5) If water reaches 100°C, it _______.

6) If I _______ time tomorrow, I will help you with the project.

7) If you mix red and blue, you _______ purple.

8) If he _______ now, he will miss the meeting later.

9) Choose the sentence that is zero conditional:

10) If they _______ earlier, they would have arrived on time. (choose best form)

11) Which sentence is a correct first conditional?

12) If you _______ the instructions carefully, problems won't occur.

13) If he _______ smoking, his health will improve next year.

14) If the alarm doesn't go off, I _______ wake you up.

15) Which is true about zero conditional?

16) If you _______ sugar in tea, it tastes sweeter.

17) If I _______ him now, he won't answer; he's in a meeting.

18) Which sentence mixes conditionals correctly for a likely future event?

19) If the shop _______ open, we can buy bread.

20) Identify the error in: 'If he will be late, call him.'