Essential and Non-Essential Grammatical Units – Answer Key
1.
non-essential
Mr. John McCarthy, who lives in Toronto, is kind and intelligent.
2.
essential
The Mr. John McCarthy who lives in Toronto is kind, but the one who lives in
Ottawa is cruel.
3.
essential
A clause which gives no necessary information is non-essential.
4.
essential
Psychiatrists who hate to talk to people are usually unsuccessful.
5.
non-esential
The second clause, which was clearly non-essential, was set off with commas.
6.
essential
All fraternity men who get caught growing marijuana will be expelled.
7.
non-essential
My great-grandfather Baldwin, who spent most of his life in Alberta, used to
make his own hickory furniture.
8.
essential
Priscilla was determined to marry no man who could not repair a wristwatch.
9.
essential
The person who draws the lucky number will receive a four-ound codfish.
10.
essential or non-essential depending on context
The old gentleman frying tomatoes is the city constable (this would be correct –
ie. essential—if there were several old gentlemen in the area) The old gentleman,
frying tomatoes, is the city constable (this would be correct – ie. non-essential – if
there were no old gentleman except one)
11.
non-essential
“Silent Night,” now being sung by the North bay Childeren’s Choir, is my
favorite carol.
12.
non-essential
Perkins, working overtime on Saturdays, hoped to finish the job by September.
13.
non-essential
The question of thermodynamics in family life, which so many sicentists have
igonored, is fully treated in one of John Black’s last books.
14.
essential
I often felt that Mrs. Twig was not fond of either of her children, but it was clearly
the daughter whom she hated.
15.
essential
Redwoods growing on the crest of mountains seldom attain a height of more than
50 feet.
Note: for this sentence, you would have to have the knowledge that redwoods
usually grow much higher.
16.
non-essential
Colonel Stone, who had been 3 years in Africa, began to grow homesick.
17.
non-essential
The Germans, who lost the war, suffered fewere casulaties than did the victors.
18.
essential or non-essential depending on how many aunts exist
My aunt, who lives in Kingston, will spend Christmas with me. (only 1 aunt
exists)
My aunt who lives in Kingston will spend Christmas with me (more than 1 aunt
so “who lives in Kingston” is essential in order to identify which aunt)
19.
essential
The old house which is situated on the hill has finally been sold.
20.
non-essential
J.B. Smith, who lives only two blocks away, owns a purple cow.
21.
non-essential
John Jiles, who just inherited a million dollars, is now celebrating in the pub!
22.
non-essential
Sally Thompson, whom you will meet tonight, is my third cousin.
23.
essential
People who know 40 languages are geniuses
24.
essential
Please help all the students who fail this exam..
25.
non-essential
The author is Samuel Johnson, who was born in England.