Grammar and reading terms · SAT Reading and Writing, ACT English, ACT Reading
Restrictive and nonrestrictive elements
Also called: Essential and nonessential clauses
Restrictive and nonrestrictive elements: A nonrestrictive element adds extra information and is set off with commas; a restrictive element is essential to the meaning and takes no commas.
By the CollegePrepRoom editorial team · Updated · How we write and check these pages
What it means
If removing a phrase changes which person or thing the sentence is about, the phrase is restrictive and should not be set off. If removing it leaves the core meaning intact, it is nonrestrictive and needs a pair of commas, dashes or parentheses.
That usually introduces restrictive clauses; which usually introduces nonrestrictive ones and follows a comma.
Example
Nonrestrictive: 'My brother, who lives in Ohio, is visiting.' (one brother) Restrictive: 'The students who finished early may leave.' (only those students)
On the exam
Comma questions on both tests often turn on whether a phrase is essential or extra information.