Употребите нужную форму сослагательного наклонения:
1.If they have a good sale, I .... by on my way home.
a)will stop
b)would stop
c)stops
2.If Diane didn't drink so much cofee, she .... so nervous.
a)woudn't be
b)will not be
c)haven't been
3.If you ...., tickets yesterday, we would have gone to the cinema.
a)have bought
b)had bought
c)will have bought
4.If they listened to us, we .... warn them.
a)can
b)could
c)will be able to