A)1.They will go to the concert if the weather is fine.
2.They will go to the concert after they do their homework.
3.They will go to the concert when they have free time.
4.They will go to the concert before you will come.
b)1.He will finish the work if you help him.
2.He will finish the work when he has necessary books.
3.He will finish the work after the teacher explain him what to do.