What is restrictive and non restrictive …

Restrictive Clause

A restrictive clause restricts or defines the meaning of a noun or noun phrase and provides necessary information about the noun in the sentence. It is not separated from the rest of the sentence by commas. Restrictive clauses are more common in writing than nonrestrictive clauses. A restrictive clause is also sometimes referred to as an essential clause or phrase.

Here are a few examples:

• The student who sits in the back of the room asks a lot of questions.
• The results that I obtained may invoke positive social change.
• The journalist whose story I read yesterday has won prizes for her work.

Nonrestrictive Clause

A nonrestrictive clause adds additional information to a sentence. It is usually a proper noun or a common noun that refers to a unique person, thing, or event. It uses commas to show that the information is additional. The commas almost act like parentheses within the sentence. If the information between the commas is omitted, readers will still understand the overall meaning of the sentence. A nonrestrictive clause is also known as a nonessential clause or phrase.

Here are a few examples:

• I want to thank my father, Mark Smith, for all of his love and support.
  • With the nonrestrictive clause omitted: I want to thank my father for all of his love and support.
• The hypothesis, which I tested throughout the research, was rejected.
  • With the nonrestrictive clause omitted: The hypothesis was rejected.