EditFast Grammar Resource: Pronouns: Pronoun Reference: Essential Clauses and Nonessential Clauses

Job SearchGovernment, corporate, military, domestic, and overseas jobs in all fields.

Resources for Writers, Authors, Editors, Copy Editors, and Proofreaders

Huge Database
Writers' and Editors' Resources
Magazines, Publishers, Literary Agents, Writing Competitions.

Copy one of the following and paste it anywhere on any page of your site.

Pronoun Reference

Essential Clauses and Nonessential Clauses

The key to choosing between that and which is knowing whether the clause to be introduced is essential or nonessential: Essential clauses limit-or more narrowly define-the meaning of the antecedent and are necessary to the meaning of the sentence.

Examples of essential clauses:

• The car that I bought yesterday is missing. (the receiver needs to know which car)
• The lake that we visited last year is now severely polluted. (identifies which lake is polluted)
• The teacher who wrote the textbook is Mr. Allen. (identifies which teacher)

Nonessential clauses give additional or supplementary information about the antecedent and could be removed from the sentence without changing the meaning of the sentence.

Examples of nonessential clauses:

• My new car, which I bought yesterday, is missing. ("which I bought yesterday" could be eliminated from the sentence without changing the meaning of the sentence)
• Snowflake Lake, which we visited last year, is now severely polluted. (additional information only-is not needed to identify which Snowflake Lake)
• Our teacher, who wrote the textbook, is Mr. Allen. (additional information- "our teacher" is not identified or differentiated by "who wrote the textbook")