From the UWF Writing Lab’s 101
Grammar Mini-Lessons Series
Mini-Lesson #40
 Are
essential to a sentence because they
restrict, or limit, the meaning of the words
they modify
 Not set off from the sentence with commas
 The
city which is known as the Mile High City has
an altitude of one mile.
 Although
they add important information,
are not essential to the meaning of a
sentence
 Set off from the sentence with commas
 Denver,
which is known as the Mile High City, has
an altitude of one mile.
Restrictive
Last summer Thaun Le visited the Vietnamese
village where she was born during the war.
He who steals my purse steals trash.
A man who thinks he has no faults has one
Good things come to people who wait.
Nonrestrictive
Margaret Thatcher, who was prime minister
longer than anyone else in this century,
made enormous changes in England.
The book, old, dirty, and dilapidated, is one
of my favorites.
The weatherman, who on a rainy day had
predicted sunshine, called the rain “Oregon
mist.”