Study materials
Two words can be removed from this sentence and it loses nothing.
The man who is waiting outside is my brother.
The man waiting outside is my brother.
That is how a relative clause is reduced. The pronoun and the form of be are dropped, and what remains attaches straight to the noun.
Two reductions, and one choice between them
When a relative clause holds who or which plus a form of be, both words can be removed. What is left depends on one thing: does the noun act, or is it acted upon.
| The noun | What remains | Example |
|---|---|---|
| performs the action | an ing form | the man waiting outside |
| undergoes the action | the third form | the report sent yesterday |
the man who is waiting outside → the man waiting outside
the report which was sent yesterday → the report sent yesterday
The mistake here is nearly always the same: an ing is chosen where the noun is really passive. So check not the form but who performs the action.
What disappears along with the reduction
Reduction is cheap but not free. Along with who and be goes the information about tense and modality.
the road which was repaired last year
the road which must be repaired
So the rule runs: reduce only when the time is clear from the context and no modal is present in the clause.
What it is for
Reductions make a text denser and remove surplus verbs. News writing and photo captions are built almost entirely from these constructions.
People living near the river were evacuated.
The documents signed yesterday are already in force.
The mistakes everyone makes
The first is taking an ing where the noun is passive.
the letter sending yesterday → the letter sent yesterday
The second is taking the third form where the noun acts.
the people lived next door → the people living next door
The third is reducing a clause that holds a modal.
the form signed by both parties → the form which must be signed by both parties
All three are caught by two questions. Does the noun perform the action or undergo it? And am I losing something important along with the reduction?
Try it right now
Take two sentences containing who is and which was and reduce them in English.
Then try to reduce a third that holds a modal. Explain to yourself why it did not work.