The words since and for can be used as conjunctions and prepositions. When they are used as conjunctions, they combine two clauses. Note that since is a subordinating conjunction whereas for is a coordinating conjunction.
When they are used as prepositions, they usually indicate time.
Since is used with the starting point of action. For shows duration.
Combine the following sentences using since or for.
1. I saw him last month. I haven’t seen him afterwards.
2. It was a public holiday. Schools and colleges remained closed that day.
3. I like him very much. So I will help him.
4. The table is made of mahogany wood. It is expensive.
5. It is raining. We can’t go out now.
6. It last rained three months ago.
7. I last visited my parents 2 years ago.
8. Something fell. I heard a noise.
1. I haven’t seen him since last month.
2. Since it was a public holiday, schools and colleges remained closed.
3. Since I like him very much, I will help him.
4. Since the table is made of mahogany wood, it is expensive.
5. Since it is raining, we can’t go out now.
6. It is three months since it rained.
7. It is 2 years since I visited my parents.
8. Something fell for I heard a noise.