An adjective clause is also called a relative clause or an adjectival clause. A clause is a group of words that have a subject and predicate. There are two kinds of clauses: independent and dependent. Independent clauses are sentences because they express a complete thought. Examples are: “The dog ran away.” and “Get the door.” In the second one, the subject is implied. To explain the function of an adjective clause, we will look at dependent clauses.
Dependent clauses have the subject and predicate but can not stand alone. They depend on another clause to have meaning. Examples are: “When you finish your work” and "unless I get more money.” With each of these, you want to ask “What?” because the thought was not finished. Dependent clauses are also called subordinate clauses and they start with a subordinate conjunction. This is the word that links the dependent clause to the rest of the sentence.
Examples of subordinate conjunctions are: how, where, when, why, unless, although, after, as far as, as if, because, before, once, whether, while, now that, until, since, and unless.
The three types of dependent clauses are:
Adjectives clauses have a subject and a verb (or predicate). They will start with a relative pronoun, like: that, who, whom, whose, or which, or a relative adverb, like why, where, or when. Adjective clauses function as an adjective and modify nouns and pronouns. They are also called relative clauses.
Just as the other dependent clauses, the adjective clause does not express a complete thought. It does not need commas separating it from the rest of the sentence if it has essential information in it; that is if you need the information it provides. If it gives additional information, then you use commas. A good way to test for this is to leave out the clause, read the sentence, and see if the meaning of the two sentences is different.
Here are some examples of adjective clauses. The adjective clause is underlined.
Since adjective clauses act like adjectives, you may want more information about adjectives. Some adjectives express the writer’s opinion of a noun or pronoun, like silly, lovely, awful, and outrageous. These are called opinion adjectives.
Some adjectives are descriptive, telling about the physical characteristics of size, shape, color, or age. Examples include: huge, wee, rectangular, oval, bluish, purple, new, and ancient.
An origin adjective tells where an object originated or where is came from. These are adjectives like: eastern, lunar, Egyptian, or German.
The composition of a noun or pronoun will be described by a material adjective. Examples are: woolen, plastic, metal, or silk.
Some adjectives tell what purpose an object is used for. These many times end with an “ing.” Some examples include: baking, fishing, testing, or hunting.
Lastly, some adjectives compare and have levels of comparison. These are words like: “good, better, best”, “dry, drier, driest”, and “beautiful, more beautiful, and most beautiful." Other adjectives compare but only on one level, like: unique, main, impossible, final, and inevitable.