Definition of Complex Sentence

A complex sentence describes a sentence structure that contains two clauses: one dependent clause and one independent clause. In simple terms, a clause is a collection of words that expresses a thought and contains a subject and a predicate. An independent clause is one that expresses a complete thought and could stand alone as its own sentence. A dependent clause, while having a subject and a predicate, expresses an incomplete thought and cannot stand alone because it contains a subordinating conjunction. When these two clauses are present together, they form a complex sentence.

Clear and coherent writing requires strong sentence structure.

Examples of Complex Sentences

Example 1: After the rain fell, the desert smelled amazing.

Example 2: Robiah worked on the surprise gift while her mom was out.

Complex Sentences from Pop Culture

There are many examples of complex sentence structure in pop culture, including song lyrics, movies, and TV shows.

Example 1:

Example 2:

Complex Sentences from Literature

Strong writing involves using a variety of sentence types and sentence lengths. Examples of all four types of sentence structures can be found in literature.

• Example 1: “When I wake up, the other side of the bed is cold.” The Hunger Games by Suzanne Collins.
• Example 2: “After you wash your mouth and learn to talk and act decent, I might cool off, too.” The Outsiders by S.E. Hinton

Strong writers use a variety of sentence structures.

Subordinating Conjunctions

Subordinating conjunctions are words that create dependency in a clause. Adding one of these words to a clause will require an independent clause to also be a part of the sentence in order to form a complete thought. There are many subordinating conjunctions, but some common ones are as follows:

• After
• Before
• Because
• When
• Until
• Since

Using Subordinate Clauses in Complex Sentences

As shown, subordinating conjunctions form dependent clauses. A complex sentence is used to show a relationship between thoughts, events, etc.

• Example 1: After the carnival ended, we went home. This shows the relationship between the ending of the carnival and the people going home, as one event triggered the other.
• Example 2: I love it when my brother comes to town. Once again, the dependent clause offers more information about the relationship between these two thoughts. In this case, the love is triggered by the brother’s arrival.

Using Complex Sentences with Other Sentence Types

Complex sentences should be used in conjunction with other sentence types in order to form clear and coherent writing. The three other types of sentence structures are as follows:

Simple Sentence

A simple sentence consists of one independent clause.

• Example: Carlos played basketball every afternoon.

Compound Sentence

A compound sentence consists of two independent clauses joined together by a comma and a coordinating conjunction or by a semi-colon.

• Example: Sheila went to the grocery store, and she found everything on her list.

Compound-Complex Sentence

A compound-complex sentence is a combination of compound and complex structures. This sentence structure contains two independent clauses and at least one dependent clause. Dependent clauses are italicized in the examples below.

• Example 1: When Eddie’s dog ran away, he felt completely lost, but his brother helped him make posters and call shelters.
• Example 2: I couldn’t concentrate while my neighbor was playing loud music, so I went to the campus library.

Problems with Writing Complex Sentences

A common mistake when writing complex sentences is to accidentally use a phrase rather than a dependent clause. A phrase is categorized as a group of words that serve a specific purpose in a sentence, but they are not clauses, meaning they do not have both subjects and predicates.

• Example 1: After work, I am going to a movie. This is a simple sentence because the phrase “after work” does not contain a subject and predicate, meaning it is not a clause.
• Example 2: The cat ran out into the street. This is also a simple sentence because “into the street” is a prepositional phrase and does not contain a subject and predicate.

Lesson Summary

To review, complex sentences are formed by using a dependent clause and an independent clause together in one sentence to express a complete thought. Things to remember:

• A clause contains both a subject and a predicate.
• A dependent clause contains a subordinating conjunction.
• A dependent clause cannot stand alone as a complete thought.
• An independent clause can stand alone as a complete thought.
• Complex sentences are just one of four types of sentence structures.