Page 103 - Grammar for Great Writing B

Common Error 7. 2 Does the adjective clause need a comma?

, ,
Abraham Lincoln who was the 16th president was the first U.S. president to be assassinated.
^ ^
who made owning slaves illegal
Abraham Lincoln was the president, who made owning slaves illegal.

RemembeR: • Use commas around adjective clauses with additional, non-essential details.
• Do not use commas around essential information. To determine if the information is
essential, take it out of the sentence. Then check if the sentence still makes sense.

ACTIVITY 5 Common Error 7.2

Read each paragraph. Underline the adjective clauses. Then add commas before and
after the nonessential adjective clauses.

1. The lima bean plant has developed a special protection against caterpillars that
eat the plant. When caterpillars start to eat the lima bean plant, the leaves release

a special scent. This scent which smells very good alerts other nearby plants of
the caterpillar danger. Then all the lima bean plants together release the same
strong scent. This scent attracts wasps which are a natural enemy of the caterpillars.
The wasps save the lima bean plants by killing the caterpillars.

2. Alcatraz Island which consists mainly of rock is a very small island in the

middle of San Francisco Bay. It is just a little over one mile from the San Francisco
shore. At first, Alcatraz was a lighthouse, but for 30 years it was a federal prison
from which escape was almost impossible. To escape, prisoners needed to be very

good swimmers. This is because the water around Alcatraz Island which is very
cold and has very strong currents has Great White sharks in it. Now Alcatraz is a
popular park which people can reach by ferry.

3. Computer Network Engineering is a relatively new field of Information
Technology. Computer network engineers who are also referred to as network

architects are the people who design and plan computer networks. They are not
the network administrators whom people call if they have computer problems.
A computer network engineer often has a specialized certificate in addition to an
undergraduate degree in network administration or computer science.

4. The first woman to travel into space, Valentina Tereshkova, was a Russian
cosmonaut. Tereshkova who was a factory worker when she applied to be a
cosmonaut was hired as a cosmonaut partly because she was also an expert skydiver.
Tereshkova’s trip into space was in the Vostok 6 which launched June 16, 1963.

Common Errors 93

Copyright 2018 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
Copyright 2018 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.
Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.
Copyright 2018 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-200-203
086-099_18606_GGW_SB_B_U7.indd 93 7/20/17 7:38 AM