Forming a complex sentence with a relative adverb

These clauses are usually connected to the main clause by the relative adverbs when, where and why.

This is the shop. The burglary was committed here.
This is the shop where the burglary was committed.

His father died. At that time he was a young boy.
At the time when his father died he was a young boy.

You didn’t accept the offer. Could you tell me the reason?
Could you tell me the reason why you didn’t accept the offer.

Forming a complex sentence with an adverb clause

An adverb clause is usually introduced by the  subordinating conjunctions when, as, since, till, where, if, though, unless, that, lest, whether, whereas etc.

I went to his office. He was not there.
When I went to his office he was not there.

There was little rain this year. The crops have dried up.
As he was little rain this year, the crops have dried up.

He has apologized. We will forget all about it.
Since he has apologized we will forget all about it.

You finish working. I will wait here.
I will wait here until you finish working.

There is heavy rainfall here. Grapes will not grow at such a place.
Grapes will not grow where there is heavy rainfall.

He is not educated. He has practical knowledge.
Though he is not educated, he has practical knowledge.

It may rain. Then the match will be cancelled.
If it rains, the match will be cancelled.