1. Hurry up or we will miss the bus.
---> If you don't hurry up, we will miss the bus.
2. Viet forgot his raincoat, so he got wet.
----> Viet got wet because he forgot his raincoat.
3. My brother plays the guitar well.
-----> My brother is good at playing the guitar
4. Study harder and you pass the examination.
------> If you study harder, you will pass the examination.
5. Tom failed the exams because of his laziness.
--------> Because Tom was lazied, he failed the exams
6. Unless we reduce the use of water and electricity we'll have to pay more this month.
-----> If we reduce the use of water and electricity, we'll have to pay less this month.
7. Lam is very good at English.
-------> Lan studies English very well
8. People throw trash onto the water, so the river is very dirty.
--->The river is very dirty because people throw trash onto the water.
9. I spent ninety minutes doing the exercises.
---> It took me ninety minutes to do the exercises.
10. Work hard or you won't pass the exam.
---> If you don't work hard, you won't pass the exam.
11. Doing morning exercise or you will be unhealthy.
-----> If you do morning exercise, you will be healthy.
12. I last saw her three years ago.
----> I haven't seen hers for three years.