An adverb clause can be shortened to an adverb phrase. This can be particularly helpful when you want to express your ideas in a more concise manner. Before you reduce an adverb clause into an adverbial phrase, make sure that the adverb clause (subordinate clause) and the main clause have the same subject.
Study the examples given below.
I slept for ten hours. I felt marvelous.
The two sentences given above express a cause and effect relationship and hence can be combined into one using the conjunction as / since.
As I had slept for ten hours, I felt marvelous.
Both clauses have the same subject and hence we can reduce the adverb clause into a phrase.
Having slept for ten hours, I felt marvelous.
Another example is given below.
He worked hard. He passed the test.
Because he worked hard, he passed the test.
This can be reduced to:
Having worked hard, he passed the test.
There are many different kinds of adverb clauses and it is not possible to reduce all of them. Generally speaking, the adverb clauses of time, cause and contrast can be reduced.
Reduced Adverb Clauses of Time
After he did military service, he became a monk.
The sentence given above can be reduced to:
After doing military service, he became a monk.
He wrote his first book after he recovered from a major illness.
This can be reduced to:
He wrote his first book after recovering from a major illness.
He feeds the cats before he goes to work.
Can be reduced to
He feeds the cats before going to work.
Reduced Adverb Clauses of Cause
Because she was late, she didn’t get tickets for the show.
This can be reduced to:
Being late, she didn’t get tickets for the show.
Because I worked fast, I finished early.
This can be reduced to:
Having worked fast, I finished early.
Because I was feeling a bit tired, I didn’t go to work.
This can be reduced to:
Feeling a bit tired, I didn’t go to work.