English Grammar Drills

64 Noun Phrases
You can never go wrong following the conservative recommendation to use that in restrictive
clauses and which in nonrestrictive. Do not expect, however, that native speakers will also follow
this advice.
Choosing between restrictive and nonrestrictive clauses
Here are two tips that will make the choice between restrictive and nonrestrictive clauses somewhat
easier:
1. It follows from the definitions given earlier that proper nouns can only be modified by
nonrestrictive adjective clauses. The reason is simple: a proper noun always refers to one specific
person, place, or thing. Since adding an adjective clause can never change who or what that
person, place, or thing is, all adjective modifiers of proper nouns must be nonrestrictive. Here are
some examples using various relative pronouns (except, of course, for that, which is best avoided
in nonrestrictive adjective clauses):
Nonrestrictive adjective clauses
Mr. Thompson, who teaches English at my school, used to live in Peru.
Mr. Thompson, whom we all adored, finally retired this year.
The Empire State Building, which is now the tallest building in New York, was completed
during the Depression.
The Shadow Café, where we had lunch recently, is just off Main Street.
The year 1776, when the Declaration of Independence was signed, is probably the most
important year in American history.
2. Common nouns that are used with an indefinite article (a/an or some) will normally take
restrictive adjective clauses. We use indefinite articles to signal that the hearer is not expected to
know in advance which particular noun we are talking about. In this sense, common nouns with
indefinite articles are the opposite of proper nouns. The function of the adjective clause is to narrow
and define the broad generic meaning of the common noun. Here are some examples:
Restrictive adjective clauses
Every morning at seven, a church that is in the neighborhood rings a bell.
He takes a pill that reduces his blood pressure.
Do you know a store that would carry computer accessories?
We are looking for a programmer who is an expert in C.
Some glasses that we got on sale have chips on their rims.
I can’t stand some commercials that are aired on late-night TV.
Some employees who work in accounting first noticed the problem last week.