Overview of Adjective Clauses

The Two Types of Adjective Clauses

I.  Restrictive (Essential) Adjective Clauses

• Restrictive adjective clauses are also called relative clauses because they relate or connect the clausal information to the preceding noun with a relative pronoun.  Restrictive (also called defining) adjective clauses define, specify (limit), or identify a noun. They are essential to the meaning of the sentence; therefore, no commas are used.

• Relative pronouns who, which, and that function as subjects of adjective clauses.

• Who and that relate to people; which and that relate to things or places.

Examples of Restrictive Adjective Clauses with subject relative pronouns:

1. People who maintain close personal ties to friends and extended family members usually cope better with illness and personal loss.

2.  A health regimen that includes a nutritious diet and regular exercise can lead to greater psychological and physical well being.

3.  Exercise activities which raise one's pulse rate are recommended for the cardiovascular system. (Note: Which is correct in restrictive clauses, but more common usage is that. To keep it simple, use that in restrictive and which in non-restrictive clauses.)

• Whom, Which, and that relate to things or places and function as objects of verbs or prepositions in adjective clauses.

Examples of restrictive adjective clauses with object relative pronouns:

1. Exercise programs that reputable health organizations promote include modifications and warnings for factors such as age and medical conditions. (That is the object of the verb promote and can be omitted: Exercise programs reputable health organizations promote...)

2.  Diet programs which we read about in popular magazines often have no medical authority behind them. (Which is the object of the preposition about and can be omitted. However, the preposition cannot be omitted: Diet programs we read about in popular magazines...)

3.  The nutritionists whom hospitals employ are experts in the dietary needs of patients with a variety of diseases. (Whom is the object of the verb employ and can be omitted. The nutritionists hospitals employ are experts in the dietary needs of patients who have a variety of  illnesses.)

4.  The nutritionist to whom you were speaking specializes in diabetes care. (Whom is the object of the preposition to and can be omitted. The preposition cannot be omitted. The nutritionist you were speaking to specializes in diabetes care.)

• Whose is the possessive relative pronoun.

• When and where function as relative adverbs. As adverbs, they can never function as the subject of adjective clauses.

Examples of restrictive adjective clauses with possessive pronoun and  relative adverb connectors:

1. The Vietnamese woman whose death from inhalation anthrax remains a mystery to investigators worked in a hospital where no anthrax spores were found.

2. Can we ever look forward to a time when we will no longer have to worry about the threat of terrorism?

II.  Non-restrictive (Non-Essential) Adjective Clauses: Non-restrictive adjective clauses give extra information about an already defined (named or specified) noun. Commas are used to set off this extra information.

Examples of non-restrictive (non-essential) adjective clauses:
(Highlighting is used to emphasize the commas in the following examples.)

1.  Kathy T. Nguyen, whose death from inhalation anthrax remains a mystery to investigators, worked in the Manhattan Ear, Nose, and Throat Hospital, where no anthrax spores were found.

2.  The Jenny Craig Diet Program, which is a multi-million dollar business, promotes  its own dietary plan and makes millions off its packaged frozen meals each year.

3. The Jenny Craig Corporation, for which the Duchess of York has made TV commercials, is a high-profile company that pitches its own program for weight management.