Complex Sentences

A complex sentence is a sentence that contains an independent clause and one or more dependent clauses. In this lesson, we will learn all about this type!

"Complex Sentences" in the English Grammar

What Are Complex Sentences?

A complex sentence is a sentence that has an independent clause and one or more dependent clauses.

The Difference between Dependent and Independent Clauses

Independent clauses can be a sentence on their own, but dependent clauses cannot stand alone, even though they have a subject and a verb.

when I arrived at the airport → dependent clause

I was a happy kid → independent clause

How to Spot a Complex Sentence?

Complex sentences are easy to identify because they often use subordinating conjunctions to connect clauses.

Subordinating Conjunctions

Subordinating conjunctions are words that are used to link an independent clause to a dependent clause. The most common subordinating conjunctions are:

  • although
  • because
  • before
  • even though
  • if
  • since
  • until
  • when

Even though he is 31, he still acts like a little child.

Michelle studied law because she wanted to become a lawyer.

a complex sentence with coordinating conjunctions

Conditional Sentences

One of the most common types of complex sentences are conditional sentences. These sentences talk about imaginary situations, often using 'if' or 'unless.'

If you want to be a successful businessman, you have to understand the language of trade.

The baby won't go to sleep unless I tell him a bedtime story.

The Difference between a Compound and Complex Sentence

Complex sentences are pretty similar to compound sentences, with only one difference: Compound sentences have two independent clauses, but complex sentences have one independent and one or more dependent clauses.

Joining Clauses Together

When an independent and a dependent clause join together to form a complex sentence, they can go in two ways:

  • the independent clause comes first:

I was snippy with him because I was running late for work.

  • the dependent clause comes first:

Because I was running late for work, I was snippy with him.


If the dependent clause comes first, it's best to separate the clauses with a comma.

Complex sentences are different from simple sentences, but share some similarities with compound sentences. Does that seem complex? Do not worry; they are easy to use once you understand how they work, which we explain fully below.

The Difference between Clause and Phrase

A clause is a group of related words containing a subject and a verb. A clause can be usefully distinguished from a phrase, which is a group of related words that does not contain a subject-verb relationship, such as 'in the morning' or 'running down the street' or 'having grown used to this harassment.' A review of the different kinds of phrases might be helpful.

Stay in the bath until the phone rings.

Leave while you can.


'Complex sentences' are used with subordinating conjunctions. They are made up of one independent clause and one or more dependant clauses. The only difference between compound and complex clauses is that compound clauses are made up of two independent clauses.

Here are some examples of complex sentences.

Although I am not good at it, I enjoyed playing basketball with John.

Since she left me, I decided to raise our child on my own.


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Sentences are formed by putting words next to each other, but we do not always need more than one word to make a meaningful sentence.

Simple Sentences

Most of us learned how to put three words together to make sentences in kindergarten: I love puppies! Games are fun! Let's learn all about simple sentences!

Compound Sentences

In this lesson, we will study compound sentences and learn how to create them by joining two or more independent clauses together.

Compound-complex Sentences

A compound-complex sentence is comprised of at least two independent clauses and one or more dependent clauses. Let's get to know it in detail!

Word Order

Word order refers to the order or arrangement of words in a phrase, clause, or sentence. In order to study them in more detail, take a look at this article!

Cleft Sentences

Cleft sentences are complex sentences that have a meaning we can express by a simple sentence. They are used to emphasize one part of a clause.

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