Active: I want him to write the letter.
Passive: I want the letter to be written/written by him(?).
Can I use 'by him'? My grammar books didn't use it.
Passive – The poor girls are married at a young age.
Active – The poor girls' parents marry them off at a young age.
Is the active voice correct? And in the passive voice, shouldn't there be an 'off'? My book left it out.
Best Answer
Converting from active to passive
What you'll need:
Instructions
Sample active clause:
Circumstance: at a young age
Putting the verb into the past tense
The original Object becomes the new Subject.
(Optionally) The original Subject becomes the new Object.
By must be added in front of it.
Any adjuncts (for instance, circumstances that apply to the entire sentence) can be re-added.
Alternately, you can omit the new Object, the Circumstance, or both, if you wish to change the information conveyed in the new sentence:
The parents are not longer portrayed as the agents of the verb.
The age of the girls are no longer conveyed.
The parents are still the age, but their age is no longer conveyed.
An interesting case: ditransitive verbs
Passivisation options:
Note
In the case of ditransitive clauses, the direct object must be present in the passive clause:
While this is technically grammatical, it doesn't have the same meaning as the Active clause, as the Active clause would now be:
Converting from passive to active
The same thing, but in reverse:
Handling cases where there is no Object in the passive
Of course, you can omit most Objects in the passive, with the exception for ditransitive verbs outlined above.
Unfortunately, without more context, you can't recover the original Subject. This is a case where the writer/speaker, has (deliberately or not) omitted the original Subject (the Agent). This can be done for many reasons, for instance to lie by omission, or in the case where the person is unaware of the Agent.
Why convert to passive?
There are many reasons to convert to passive:
In fact, linguistically, the process of changing the grammatical roles from Subject to Object and Object to Subject is called demotion and promotion, respectively.
1 I say a real subject, because relational, existential, and meteorological clauses, which technically have subjects can't be passivised.
Passivisations:
While The Pope is him/he is grammatical, it isn't really passivisation.
Interestingly, putting attributive clauses into the past tense can give them a passive-like construction.
This is a much larger can of worms, and it depends largely on the context as to whether it is a passivised clause or just an adjectival usage.