A dependent clause
cannot stand alone as a sentence
. In itself, a dependent clause does not express a complete thought
; therefore, it is usually attached to an independent clause
. Although a dependent clause contains a subject
and a predicate
, it sounds incomplete when standing alone. Some grammarians use the term subordinate clause
as a synonym for dependent clause,
but in the majority of grammars, subordinate clause
refers only to adverbial dependent clauses.
A dependent clause usually begins with a dependent word. One kind of dependent word is a subordinating conjunction
. Subordinating conjunctions are used to begin dependent clauses known as adverbial clauses
which act like adverbs
. In the following examples, the adverbial clauses are bold and the subordinating conjunctions are italicized:
- Wherever she goes, she leaves a piece of luggage behind. (The adverbial clause wherever she goes modifies the verb leaves.)
- Bob enjoyed the movie more than I did. (The adverbial clause than I did modifies the adverb more.)
Another type of dependent word is the relative pronoun. Relative pronouns begin dependent clauses known as adjective clauses, which act like adjectives, or noun clauses, which act like nouns. In the following examples, the dependent clauses are bold and the relative pronouns are italicized:
- The only one of the seven dwarfs who does not have a beard is Dopey. (The adjective clause who does not have a beard describes the noun one.)
- No one understands why experience is something you don't get until just after you need it. (The noun clause why experience is something you don't get until just after you need it functions as a direct object.)
Dependent clauses are classified further into:
- Noun clause
- Adverbial clause
- Adjective clause
A noun clause is always a clause that can be used in the same way as a noun, adjective, verb, or pronoun. It can be a subject, predicate nominative, direct object, appositive, indirect object, or object of the preposition. Some of the words that introduce noun clauses are that, whether, who, why, whom, what, how, when, whoever, where, and whomever. Notice that some of these words also introduce adjective and adverbial clauses. (To check a noun clause substitute the pronoun it or the proper form of the pronouns he or she for the noun clause.) Examples:
- I know who said that. (I know it.)
- Whoever said it is wrong. (He is wrong.)
Sometimes a noun clause is used without the introductory word. Example:
- I know that he is here. (I know he is here.)
An adjective clause—also called an adjectival or relative clause—will meet three requirements. First, it will contain a subject and verb. Next, it will begin with a relative pronoun [who, whom, whose, that, or which] or a relative adverb [when, where, or why]. Finally, it will function as an adjective, answering the questions What kind? How many? or Which one? The adjective clause will follow one of these two patterns:
- Relative Pronoun [or Relative Adverb] + Subject + Verb = Incomplete Thought
- Relative Pronoun [Functioning as Subject] + Verb = Incomplete Thought
- Whose big, brown eyes pleaded for another cookie
- Whose = relative pronoun | eyes = subject | pleaded = verb
- Why Fred cannot stand sitting across from his sister Melanie
- Why = relative adverb | Fred = subject | can stand = verb [not, an adverb, is not officially part of the verb]
- That bounced onto the kitchen floor
- That = relative pronoun functioning as subject | bounced = verb
- Who hiccuped for seven hours afterward
- Who = relative pronoun functioning as subject | hiccuped = verb
- Grim, who took Hissy's life, went away to the underworld.
In formal English grammar, sentence fragments are typically avoided. Since an adjective clause does not express a complete thought, it cannot stand alone as a sentence. Writers who want to avoid sentence fragments must connect each adjective clause to a main clause. In the examples below, notice that the adjective clause follows the word that it describes.
- Diane felt manipulated by her beagle Santana, whose big, brown eyes pleaded for another cookie.
- Chewing with her mouth open is one reason why Fred cannot stand sitting across from his sister Melanie.
- Growling ferociously, Oreo and Skeeter, my two dogs, competed for the hardboiled egg that bounced onto the kitchen tile.
- Laughter erupted from Annamarie, who hiccuped for seven hours afterward.
Punctuating adjective clauses can be problematic. For each sentence, the writer will have to decide if the adjective clause is essential or nonessential and use commas accordingly. Essential clauses do not require commas. An adjective clause is essential when the information it contains is relevant to the overall message. For example:
- The vegetables that people often leave uneaten are usually the most nutritious.
Vegetables is nonspecific. To know which ones we are talking about, we must have the information in the adjective clause. Thus, the adjective clause is essential and requires no commas.
If, however, we eliminate vegetables and choose a more specific noun instead, the adjective clause becomes nonessential and does require commas to separate it from the rest of the sentence. Read the correct form:
- Broccoli, which people often leave uneaten, is very nutritious.
"He saw Mary when he was in New York" and "They studied hard because they had a test" both contain adverbial clauses (in italics). Adverbial clauses express when, why, opposition and conditions and are dependent clauses. This means that an adverbial clause can not stand by itself - in other words, "When he went to New York." is not a complete sentence. It needs to be completed by an independent clause. Example:
- He went to the Guggenheim museum when he was in New York.
Dependent clauses and sentence structure
A sentence with an independent clause
and one or more dependent clauses is referred to as a complex sentence
. One with two or more independent clauses and one or more dependent clauses is referred to as a compound-complex sentence
- My sister cried because she scraped her knee. (complex sentence)
- Subjects: My sister, she
- Predicates: cried, scraped her knee
- Subordinating conjunction: because
- When they told me I won the contest, I cried, but I didn't faint. **(compound-complex sentence)
- Subjects: they, I, I, I
- Predicates: told me, won the contest, cried, didn't faint
- Subordinating conjunctions: When, that (understood)
- Coordinating conjunction: but
The above sentence actually contains two dependent clauses. "When they told me" is one; the other is "(that) I won the contest." The "that" is understood to precede the "I won" and functions as a subordinating conjunction.
Non-finite dependent clauses
Dependent clauses may be headed
by an infinitive
or other non-finite verb
form. In these cases, the subject of the dependent clause may take a non-nominative
- I want him to vanish.
- I saw you wandering around.
- Rozakis, Laurie (2003). The Complete Idiot's Guide to Grammar and Style pp. 153–159. Alpha. ISBN 1-59257-115-8.