Restrictive Relative Clauses vs Non-Restrictive Relative Clauses

Restrictive Relative Clauses

A restrictive relative clause (also known as a defining or essential clause) provides essential information about the noun it modifies, restricting or defining its meaning. Without this clause, the meaning of the sentence would be incomplete or unclear. Restrictive relative clauses are not set off by commas.

Example:

• The book that you gave me is really interesting.
  • Here, "that you gave me" is essential to specify which book is interesting. Without it, the meaning of "the book" would be too broad.

Key Features:

1. Essential Information: The clause is necessary to understand the noun fully.
2. No Commas: Restrictive clauses are not separated by commas.
3. Relative Pronouns: Commonly use that, who, whom, whose, which. In informal usage, that is often preferred over which in restrictive clauses when referring to things.
4. Subject-Verb Agreement: The verb in the clause agrees with the noun it modifies.

Examples:

• People who exercise regularly tend to be healthier.
  • "Who exercise regularly" restricts the meaning to only people who exercise.
• The car that I bought last year has broken down.
  • "That I bought last year" restricts the meaning to the specific car the speaker purchased.

Non-Restrictive Relative Clauses

A non-restrictive relative clause (also known as a non-defining or non-essential clause) provides extra information about the noun it modifies. The sentence would still make sense without the clause because the noun is already clear. Non-restrictive relative clauses are always set off by commas.

Example:

• The book, which I bought yesterday, is really interesting.
  • Here, "which I bought yesterday" is additional information. The noun "the book" is already defined, and the clause simply adds more detail.

Key Features:

1. Non-Essential Information: The clause adds extra, non-essential details about the noun.
2. Commas: Non-restrictive clauses are set off by commas.
3. Relative Pronouns: Commonly use which, who, whom, whose, but never that in non-restrictive clauses.
4. More Flexible Positioning: These clauses can often be omitted without changing the sentence’s core meaning.

Examples:

• My brother, who lives in New York, is visiting us next week.
  • "Who lives in New York" is additional information about the brother; the sentence would still make sense without it.
• The Eiffel Tower, which is in Paris, is a popular tourist attraction.
  • The clause "which is in Paris" adds extra information about the Eiffel Tower, but it’s not necessary for understanding what the Eiffel Tower is.

Key Differences

FeatureRestrictive ClausesNon-Restrictive Clauses

Function	Essential to defining the noun	Adds non-essential, extra information
Punctuation	No commas	Commas used
Relative Pronouns	That, who, whom, which	Which, who, whom, whose (never that)
Omission Impact	Sentence meaning changes if omitted	Sentence meaning remains the same if omitted
Formality	Often seen in more formal and precise writing	Used in both formal and informal writing

Academic References:

1. Huddleston, R., & Pullum, G. K. (2002). The Cambridge Grammar of the English Language. Cambridge University Press.
   • This is a comprehensive guide to English grammar and includes detailed explanations of relative clauses.
2. Quirk, R., Greenbaum, S., Leech, G., & Svartvik, J. (1985). A Comprehensive Grammar of the English Language. Longman.
   • A detailed academic source explaining relative clauses and other key grammatical structures.
3. Biber, D., Johansson, S., Leech, G., Conrad, S., & Finegan, E. (1999). Longman Grammar of Spoken and Written English. Longman.
   • This book offers insights into how relative clauses are used differently in spoken and written English.