Раскрывая скобки, напишете каждое предложение три раза, построив условные предложения i, ii и iii типов. образец: if you (to be) free, i (to come) to see you. if you are free, i will come to see you. if you were free, i would come to see you. if you had been free, i would have come to see you. 1) if he (not to come) in time, we (to wait for) him. 2) if you (to put on) your glasses, you (to see) better. 3) if you (not to work) systematically, you (to fail) at the examination. 4) if he (to be) ill, he (not to take) part in the football match. 5) if we (not to have) so much luggage, we (to walk).

1) If he doesn't come in time, we will wait for him.
If he didn't come in time, we would wait for him.
If he had come in time, we would have waited for him.  

2) If you put on your glasses, you will see better.
If you put on your glasses, you would see better.
If you had put on your glasses, you would have seen better.  

3) If you don't work systematically, you will fail at the examination.
If you didn't work systematically, you would fail at the examination.
If you hadn't worked systematically, you would have failed at the examination.  

4) If he is ill, he won't take part in the football match.
If he was ill, he wouldn't take part in the football match
If he had been ill, he wouldn't have taken part in the football match  

5) If we don't have so much luggage, we will walk.
If we didn't have so much luggage, we would walk.
If we hadn't had so much luggage, we would have walked.