What Is a Complex Sentence? | Examples & Definition
A complex sentence consists of an independent clause (e.g., “I will love you”) and one or more dependent clauses (e.g., “until the end of time”).
Complex sentences are one of the four sentence structures in English. The others are simple sentences, compound sentences, and compound-complex sentences.
If you go to the store, will you pick up some milk?
My cousin, who lives in Germany, is coming to visit next week.
Lock the door when you leave.
What is a complex sentence?
A complex sentence is made up of two types of clauses (a group of words with a subject and a verb):
- An independent clause (sometimes called a main clause), which can stand on its own as a sentence (e.g., “I want a snack”)
- At least one dependent clause (sometimes called a subordinate clause), which typically begins with a word called a dependent marker and cannot stand on its own as a sentence (e.g., “before I go to bed”)
Dependent clauses must be joined to an independent clause to form a complete sentence. The resulting sentence is classified as complex (e.g., “I want a snack before I go to bed”).
Can you wait until I get back?
The bag that has a blue strap is mine.
After Ramit left, we went to the deli because we were hungry.
Dependent clauses in complex sentences
To identify complex sentences, you must be able to identify dependent clauses. There are two types of words that begin a dependent clause: subordinating conjunctions and relative pronouns.
Subordinating conjunctions
Clauses that begin with subordinating conjunctions (e.g., “until,” “because,” “if”) are adverbial clauses. When they are placed before the independent clause, a comma is required. When they follow the independent clause, a comma is typically not required.
Because it was raining, the game was canceled.
Relative pronouns
Relative pronouns (e.g., “that,” “which,” “who”) are used to begin two types of dependent clauses: adjective clauses and noun clauses.
The employee who sells the most subscriptions will win a prize.
I want the necklace that Olivia is wearing.
Some people do not believe that a college education is necessary.
- Relative pronouns can act as the subject of a clause. Sometimes, people don’t realize that the dependent clause is a separate clause because they don’t see a traditional subject (e.g., “which has over 100,000 miles”).
- Relative pronouns are sometimes omitted. Even if the relative pronoun is omitted (e.g., “I want the necklace [that] Olivia is wearing”), the sentence is still complex.
- Adjective clauses sometimes break up the independent clause. It is sometimes difficult to see the sentence as two distinct clauses. For example, in the sentence “The storm that started Thursday ended today,” the independent clause is “The storm ended today.”
Compound vs complex sentences
There are four sentence structures in English, as shown in the following table. They are differentiated by the number of independent and dependent clauses they have.
| Type | Components | Example |
|---|---|---|
| Simple | One independent clause | Mario cleaned the kitchen. |
| Compound | Two or more independent clauses joined by a coordinating conjunction or semicolon | Mario cleaned the kitchen, and Jen washed the windows. |
| Complex | One independent clause and one or more dependent clauses | Before the guests arrived, Mario cleaned the kitchen. |
| Compound-complex | Two or more independent clauses and one or more dependent clauses | Before the guests arrived, Mario cleaned the kitchen, and Jen washed the windows. |
As you can see, compound sentences are made up of at least two independent clauses, while complex sentences have only one independent clause and at least one dependent clause.
Frequently asked questions about complex sentences
- What is the difference between a complex sentence and a compound sentence?
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Complex sentences are made up of one independent clause and at least one dependent clause.
Compound sentences are made up of two or more independent clauses connected with a coordinating conjunction or a semicolon.
Complex vs compound sentence examples Complex sentence Compound sentence If it stops raining, I will go to the park. It stopped raining, so I went to the park. Kya was sleeping while the teacher was talking. The teacher was talking, and Kya was sleeping. QuillBot’s Paraphraser can help you vary your sentence structure to improve your writing.
- What is an example of a complex sentence?
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An example of a complex sentence is “Desmond likes to stretch before he runs.” It is made up of one independent clause (“Desmond likes to stretch”) and a dependent clause (“before he runs”).
QuillBot’s Grammar Checker can help ensure you’re using complex sentences correctly.
- Which word signals a nonrestrictive clause in a complex sentence?
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The relative pronouns “which,” “who,” “whom,” and “whose” can all be used to signal a nonrestrictive clause in a complex sentence.
These pronouns often introduce an adjective clause (or relative clause), which is a type of dependent clause. When that dependent clause is connected to an independent clause, it forms a complex sentence.
Adjective clauses can be either restrictive or nonrestrictive. Nonrestrictive clauses are set off with commas.
Nonrestrictive clauses in complex sentences examples Camila ordered an americano, which is an espresso and water.My best friend, who is named Ana, is coming to visit me.
The CEO, whom most people assumed was going to retire, took a job at another company.
Emilio, whose apartment I am renting, has decided to move back to town.
Note that the relative pronoun “that” is only used in restrictive clauses.
QuillBot’s Grammar Checker can help you ensure your writing is free of errors.
