1. By Holly Cin
5EF/Summer 2012

4.  This information identifies the noun and is
therefore necessary.
 Example: The teacher who teaches 5E is an
excellent teacher.
 “who teaches 5E” is essential information;
otherwise you don’t know which teacher we are
referring to and the sentence isn’t clear.
 Essential clauses are attached to the antecedent
(noun) WITHOUT COMMAS to separate them.

5.  This information does not identify the noun and is
therefore EXTRA. You can remove this adjective
clause and the sentence will still be clear.
 Example: Holly Cin, who teaches 5E, is an excellent
teacher.
 “who teaches 5E” is extra information here since
you already know who Holly Cin is; she has been
identified by name. Therefore, any information you
give me about Holly Cin is now EXTRA.
 NON-Essential clauses are separated from their
antecedents (nouns) WITH COMMAS.

6.  When commas are used, the pronoun THAT may
not be used (only
WHO, WHOM, WHICH, WHOSE, WHERE, and WHEN
may be used, and object pronouns cannot be
omitted.
 Ex: My mother, whom I owe my life to, is a
remarkable woman.
 Incorrect: My mother, THAT I owe my life to, is a
remarkable woman.
 Incorrect: My mother, I owe my life to, is a
remarkable woman.

7.  Proper names are always followed by non-
essential clauses.
 Ex. Texas, which is the largest state in the
continental U.S., is famous for oil, cowboys, and
the University of Houston.
 Since we already know what Texas is, any
information that follows it is NON-essential, and
therefore, separated by commas.
 We could remove the non-essential clause and
still understand the sentence 100%.

8.  Proper names are always followed by non-
essential clauses.
 Ex. Greg Urquhart, who has been teaching at the
LCC since time immemorial, has a great sense of
humor.
 Since we already know who Greg Urquhart is, any
information that follows is NON-essential, and
therefore, separated by commas.
 We could remove the non-essential clause ad still
understand the sentence 100%.

9.  Once the person or thing has been
identified, all information which follows in an
adjective clause becomes non-essential.
 Ex. We had rice and beans for dinner last
night. The rice, which was prepared with
onions and garlic, tasted delicious.
 In the above example, you know which rice
we’re talking about in the second sentence
because it has been identified in the first
sentence.

10.  Compare the meaning of the following two
sentences. In one case, the information in the
adjective clause is essential to the meaning; in
the other, it is extra.
 1. We took some children on a picnic. The
children, who wanted to play soccer, ran to an
open field as soon as we arrived at the park.
 2. We took some children on a picnic. The
children who wanted to play soccer ran to an
open field as soon as we arrived at the park. The
others played baseball.

11.  Compare the meaning of the following two
sentences. In one case, the information in the
adjective clause is essential to the meaning; in
the other, it is extra.
 1. I met with some students after class
yesterday. The students, who were from 5E, had
prepared lots of good questions for me to
answer.
 2. I met with some students after class
yesterday. The students who were from 5E had
lots of good questions. The students who were
from 5F had nothing at all to say.

12. 1. I met with some students after class yesterday. The
students, who were from 5E, had prepared lots of
good questions for me to answer.
In this case, all of the students were from 5E so the
adjective clause “who were from 5E” was not
essential to identify them.
 2. I met with some students after class yesterday.
The students who were from 5E had lots of good
questions. The students who were from 5F had
nothing at all to say.
 In this case, some of the students were from 5F and
some were from 5E so the adjective clause “who were
from 5E” was essential to identify them.