Reduced Adverb Clause

You may have been familiar with reducing adjective clauses to modifying adjective phrases (participle phrase). Similarly, some adverb clauses may also be reduced to modifying adverb phrases, too.

For examples,

  •  While I was working there, I made contacts with lots of customers.
  → While working there, I made contacts with lots of customers.

  •  Before I resigned, I built a strong team there.
  → Before resigning, I built a strong team there.


Notice: An adverb clause can be reduced only if the subject of the adverb clause and the subject of the main clause are the same. The modifying phrase modifies the subject of the main clause.

  •  While I was sitting in the class, I fell asleep.
  → While sitting in the class, I fell asleep.       [Correct]

  •  While teacher was teaching, I fell asleep.
  → While teaching, I fell asleep.         [Incorrect]

HOW TO REDUCE ADVERB CLAUSES

Method 1: Omit the subject and verb "to be" in the adverb clause.

For examples,

  •  While he was walking to his school, he met his old friend.
  → While he was walking to his school, he met his old friend.
  → While walking to his school, he met his old friend.

  •  She identifies a problem while she is installing a new software.
  → She identifies a problem while she is installing a new software.
  → She identifies a problem while installing a new software.

Method 2: If there is no verb to be, omit the subject and change verb to -ing form.

For examples,

  •  Before he got rich, he worked very hard.
  → Before he got rich, he worked very hard.
  → Before getting rich, he worked very hard.

  •  She has been working in a law firm after she has graduated in laws.
  → She has been working in a law firm after she has graduated in laws.
  → She has been working in a law firm after having graduated in laws.
  or; → She has been working in a law firm after graduating in laws.

The difference in meanings

Expressing the meaning of "being at the same time". 

For examples,

  •  While he was studying at university, he also worked as a sales freelancer.
  → While he was studying at university, he was also working as a sales freelancer.
  → While studying at university, he also worked as a sales freelancer.
  → Studying at university, he also worked as a sales freelancer.
        [We can also omit the clause marker "while". The sentence conveys the same meaning]

  •  While they are flying, passengers can enjoy funny video clips.
  → While they are are flying, passengers can enjoy funny video clips.
  → While being flying, passengers can enjoy funny video clips.
  or → Being flying, passengers can enjoy funny video clips.
  or → While flying, passengers can enjoy funny video clips.
  or → Flying, passengers can enjoy funny video clips.

Expressing the meaning "cause and effect" 

Notice:

1. "because" is omitted, but the –ing phrase expresses the cause and effect relationship.
2. "Having + past participle" gives the meaning not only of "because" but also of "before." 

For examples,

  •  Because he was late for a meeting, he ran up the stairs very fast.
  → Because he was late for a meeting, he ran up the stairs very fast.
  → Being late for a meeting, he ran up the stairs very fast.
  or → Late for a meeting, he ran up the stairs very fast.
  or → Having been late for a meeting, he ran up the stairs very fast.

  •  Because they hadn't studied hard, they failed in the final exams.
  → Because they hadn't studied hard, they failed in the final exams.
  → Having not studied hard, they failed in the final exams.
  or → Not studying hard, they failed in the final exams.
  or → Having had not studied hard, they failed in the final exams.

  •  Because she was sick, she went to see a doctor.
  → Because she was he was sick, she went to see a doctor.
  → Being sick, she went to see a doctor.
  or → Having been sick, she went to see a doctor.

Upon 

"Upon + v-ing" expresses the meaning of "when" or "shortly after".

For examples,

  •  Upon he finishes his study in Japan, he will come back to Cambodia.
  → Upon finishing his study in Japan, he will come back to Cambodia.

Note: "On" can be used to replace "Upon". For examples,

  •  Upon he gets the new position, he need to learn a lot of new things.
  → Upon getting the new position, he need to learn a lot of new things.
  or → On getting the new position, he need to learn a lot of new things.