Select the option that expresses the given sentence in active voice. Trigonometry has been taught by him for donkey’s years.
- (a)He has been teaching trigonometry for donkey’s years.
- (b)He had been teaching trigonometry for donkey’s years.
- (c)He is teaching trigonometry for donkey’s years.
- (d)He has been trigonometry teaching for donkey’s years.
Answer
Why
Correct — A. Take the passive apart: object Trigonometry, verb has been taught, agent by him.
Converting to active promotes the agent to subject (he) and pushes the object after the verb. The auxiliary has been fixes the time as present perfect, and voice conversion never moves the tense.
Option (a) keeps the present perfect and the ordinary verb-then-object order, and the duration phrase for donkey's years is exactly what the perfect continuous has been teaching is used for.
Why the others are wrong
- (b)He had been teaching trigonometry for donkey’s years. — Had been teaching is past perfect continuous. The original auxiliary is has been, not had been, and nothing in the sentence sets up an earlier past event for the teaching to precede.
- (c)He is teaching trigonometry for donkey’s years. — Is teaching is present continuous. It drops the perfect aspect, so the stretch of time reaching back into the past — the whole point of for donkey's years — disappears.
- (d)He has been trigonometry teaching for donkey’s years. — Trigonometry teaching is the wrong word order. English puts the object after the verb, and has been trigonometry teaching reads as a compound noun rather than a verb with its object.
Concept
Voice conversion is three mechanical moves. The agent in the by-phrase becomes the subject, the subject of the passive becomes the object, and the by-phrase is dropped.
The one thing you never touch is the tense. If the passive is present perfect, the active is present perfect; if it is past continuous, the active is past continuous.
Three of the four options here fail on that single test or on word order, so you can decide the item without weighing meaning at all.
A one-to-one conversion of has been taught would be he has taught, which is not offered.
The perfect continuous in option (a) is what the paper takes, and it is the only choice that both holds the present perfect and keeps the verb before its object.
Key facts
- In a passive sentence the doer sits in the by-phrase, and conversion to active makes that doer the subject.
- Voice conversion preserves the tense: has been taught is present perfect, so the active stays present perfect.
- Donkey's years is an idiom meaning a very long time.
- The perfect continuous passive (has been being taught) is avoided in ordinary English, so perfect continuous actives usually face a simple perfect passive.
Study next
Common traps
- Shifting has been to had been, which changes the tense the conversion has to preserve
- Accepting the option that keeps the object in front of the verb because it starts correctly with He
A present perfect passive turns active on 26 Sep 2024, 16:00, English Q.5, where How have they been ordered by the minister? becomes How has the minister ordered them?, and a past continuous passive on 11 Sep 2024, 16:00, English Q.15.
The reverse direction, active into passive, is asked in this paper at English Q.13, where Mr. Amar refused him admittance has to be turned round.
Related PYQs
No directly related past PYQ was found.