Adjective Clauses
An adjective clause (also called a relative clause) modifies a noun or pronoun. Usually it immediately follows the word or words modified and is introduced by a relative pronoun-who, whom, whose, which, that, whoever, whomever, or whatever - or by the subordinating conjunction when or where.
Ted’s old Volkswagen, which had a badly rusted body, still ran like a dream.
My grandmother remembers a time when Volkswagens were not on the market.
If the relative pronoun or subordinating conjunction (the subordinator) introducing an adjective clause does not function as the subject of the subordinate clause, you can omit it. In fact, omitting it picks up the pace of the sentence.
The Volkswagen that Janie saw at the car show was restored down to the smallest detail.
If the subordinator is the subject of the adjective clause, you can usually rewrite the sentence to eliminate unneeded words.
A statue of Louis Riel, which is made of marble, is in front of City Hall. [for marble could become]
A marble statue of Louis Riel, is in front of City Hall.
