1.The child is crying because his mother isn't here 
= if his mother .......were here, the child wouldn't be crying......
2. I got a ticket because I drove too fast.
= if I hadn't........driven too fast, i would have got a ticket..................
3. It is raining, so I won't go with you 
= if it wasn't ........raining, I would go with you..............
4. I didn't buy this coat because I didn't have enough money.
= if I had ......had enough money, I would have bought this coach ..............
5. Mảy didnn't pass the final exam because she didn't study hard.
= if Mary ......had studied hard, she would have passed............