Sometimes when we use clauses, we can make them shorter and simpler by using adverb phrases. Adverb phrases use gerunds.
Since he doesn't have a coach, he's not a very experienced volleyball player.
In this case, we can't shorten it by using a prepositional phrase because we can't make a short phrase with only a preposition and a noun.
So instead, we shorten it by using gerunds.
| Adverb Clause | Since he doesn't have a coach, he's not a very experienced volleyball player. |
| Adverb Phrase | Not having a coach, he's not a very experienced volleyball player. |
By changing the word 'have' into a gerund, you can shorten the sentence.
It is important to remember that this only works if the subject is the same in both clauses of a sentence. It doesn't work if the subject is different.
| Adverb Clause | Adverb Phrase | |
| Same Subjects | While I was running outside, I fell and broke my ankle. | While running outside, I fell and broke my ankle. |
| Different Subjects | While Maggie was running outside, June fell and broke his ankle. |
Because the subjects in the two clauses in the second example are different, you cannot remove the subject and make an adverb phrase.
Most adverb clauses are made by removing the subject and any auxiliary from the clause. An auxiliary is a helping verb in front of the main verb. Your clause may or may not have an auxiliary.
While Peter was waiting for his test results, he became very anxious and nervous.
In the example, 'Peter' is the subject. You can remove that. 'Was' is the auxiliary. You can remove that, too.
While Peter was waiting for his test results, he became very anxious and nervous.
Because the original sentence was in the continuous form, the verb 'wait' was already in the gerund form. You don't even need to change it.
Some sentences may not have an auxiliary.
| Adverb Clause | Before she goes for a run, she stretches. |
| Adverb Phrase | Before |
If the clause is negative, leave the word 'not'.
| Adverb Clause | When she isn't working in her office, she's usually outside enjoying the sunshine. |
| Adverb Phrase | When |
When you are using clauses to give reasons, you should leave out the subordinator as well. Look at the sentence below.
Because she is sick, Maggie won't have to take the test today.
In this case, we can remove 'because' and 'she' and change the 'is' into the gerund form: 'being'.
Because she is Being sick, Maggie won't have to take the test today.
Here are some examples of sentences with adverb clauses reduced to phrases.

Since he had never given a speech before, he was very nervous.
Having never given a speech before, he was very nervous.

Since they won the championship, they have become local celebrities!
Having won the championship, they have become local celebrities!

Because she didn't eat dinner, she had lots of dessert.
Not having eaten dinner, she had lots of dessert.
Exercise
Please open the exercise to continue.