Complex Sentence: Types, Rules, Definition and Examples

What Is a Complex Sentence?

A complex sentence is a type of multi-clause sentence that consists of one independent clause and at least one dependent clause. These clauses are linked by subordinating conjunctions or relative pronouns. Complex sentences are useful for demonstrating the connections between ideas and providing additional information within a sentence.

Moving further, look below for the complex sentence definition and examples according to the popular dictionaries:

• Oxford Learner’s Dictionary- “containing one main part (main clause of a sentence) and one or more other parts (called affixes or subordinating clauses)”.
• Collins Dictionary- “a sentence containing at least one main clause and one subordinate clause.”
• Macmillan Dictionary- “a sentence consisting of an independent clause and one or more subordinate clauses.”

Take a look below at some examples of complex sentences for your better understanding:

• The hotel, where we had our farewell dinner, is being shut down.
• I will be on my way when my brother picks me up.

These are the complex sentence definitions and examples for your reference.

Structure of Complex Sentence

A complex sentence is created by combining an independent clause with at least one dependent clause. While the independent clause can stand alone as a complete sentence, the dependent clause cannot stand alone and only adds additional information to the independent clause.

Take a look below to understand the complex sentence structure in detail:

Independent Clause + Subordinating Conjunction + Dependent Clause  

• Independent Clause: It is the main part of the sentence that expresses the main idea and can stand alone.

For example: The dog was sleeping.

• Dependent Clause: This clause provides additional information and cannot be used alone.

For example, because she was sleeping.

• Subordinating Conjunctions: These conjunctions connect the dependent clause to the independent clause, showing the relation between two sentences. (because, although, while, since. If, when, after)

For Example: Although it was raining, we went for a walk.

Now you have understood the complex sentence structure. Let’s take a look below to know its rules.

Rules of Complex Sentence

When using complex sentences, it's important to follow specific English grammar rules to ensure proper usage. Here are the key rules for constructing complex sentences:

Rule 1: One Independent Clause Required

A complex sentence must contain one independent clause and at least one dependent clause.

Rule 2: Use Subordinating Conjunctions

Dependent clauses are introduced by subordinating conjunctions such as: when, where, before, after, if, unless, and others.

Rule 3: Punctuation Guidelines 

If the dependent clause comes first, place a comma after it. However, if the independent clause comes first, no comma is needed.

Rule 4: Dependent Clauses Cannot Stand Alone

A dependent clause cannot function as a complete sentence, so it should never be written alone.

Rule 5: Relative Clauses Modify Nouns

Relative clauses describe or identify a noun and typically follow the noun they modify.

Rule 6: Noun Clauses as Subjects or Objects

A noun clause can serve as the subject, object, or complement within a sentence. 

Rule 7: Avoid Comma Splices and Run-ons 

Complex sentences should properly join ideas using subordinating conjunctions; therefore, avoid using commas to connect independent clauses.

By following these complex sentence rules, you can create clear and grammatically correct sentences.

Types of Complex Sentences with Examples

There are three types of complex sentences: Adverbial, Noun Clause, and Relative.

1. Adverbial Complex Sentences 

These types of sentences contain a dependent clause that functions as an adverb, which provides additional information about the main clause. It often modifies the verb or the entire sentence. It provides information about the main clause, answering questions like why, when, where, how, to what extent or under what conditions.

Take a look below for some examples of complex sentences for better understanding:

1. As soon as the bell rings, the students rush out of the school.

2. Whenever he feels stressed, he goes for a walk.

3. Because it was raining heavily, we decided to stay home.

4. While I was in the bathroom, the phone rang.

5. Even though she was sick, she went to work.

2. Relative Complex Sentences (Adjective Clauses)

Relative complex sentences include a dependent clause that functions as an adjective, modifying a noun in the main clause. Moreover, adjective clauses often begin with relative pronouns (who, whom, whose, which, that).

Take a look below for some example of complex sentence for better understanding:

1. The car that he bought last month is very fuel-efficient.

2. The team whose performance was the best won the championship.

3. The cafe where we had dinner last week is very popular.

4. The series that we watched last night was really scary.

3. Noun Clause Complex Sentences

Complex sentences contain a dependent clause that functions as a noun. They can act as a subject, object, or complement in the sentence. Dependent Clauses: that, what, whatever, who, whoever, how, why, whether, if and more.

Take a look below for some example of complex sentence for better understanding:

1. The fact that he was late. 

2. We will be going picnic if the weather is good.

3. What she said.

4. His idea is that we should try something new.

5. I am worried about what will happen.

These are examples of complex sentences for your reference.

Practice Exercises for Complex Sentences

Convert each pair of sentences into a complex sentence, using the provided subordinating conjunction:

1. I was sleepy. I went to bed. (Because)

2. He didn’t feel well. She didn’t go to school. (Because)

3. He works hard. He will succeed. (If)

4. The weather was good. We stayed home. (Since)

5. The food was delicious. We ate a lot. (Because)

6. He was sick. He didn’t go to school. (Because)

7. The series was boring. We left early. (Because)

8. It was a holiday. We went to the beach. (Since)

9. It was snowing. We went for a walk. (Although)

10. He didn’t study. He failed the exam. (Because)

Answers:

1. Because I was sleepy, I went to bed.

2. Because he didn’t feel well, he didn’t go to school.

3. If he works hard, he will succeed.

4. Since the weather was bad, we stayed home.

5. Because the food was delicious, we ate a lot.

6. Because he was sick, he didn’t go to the office.

7. Because the series was boring, we left early.

8. Since it was a holiday, we went to the beach.

9. Although it was snowing, we went for a walk.

10. Because he didn’t study, he failed the exam.

Conclusion

In summary, this blog explored the concept of complex sentences in English grammar. By now, you should have a clear understanding of what a complex sentence is, its various types, the rules governing it, its structure, and even some exercises for practice. If you have any questions or doubts, please don’t hesitate to reach out to our experts. They are here to help you every step of the way and ensure you don’t face any challenges alone.

Read More:  Simple Sentence, Imperative Sentence, Exclamatory Sentence, Compound Sentence

FAQS

1. What Is a Complex Sentence?

A complex sentence is a sentence that combines an independent clause with at least one dependent clause. Moreover, the dependent clause is often introduced by a subordinating conjunction.

For Example: because, although, if, while, or relative pronoun.

2. How to Identify a Complex Sentence?

A complex sentence is identified by having both an independent clause and at least one dependent clause, connected by a subordinating conjunction or relative pronoun. However, the independent clause can stand alone as a complete sentence, while the dependent clause cannot.

3. What Is the Difference Between a Simple and a Complex Sentence?

A simple sentence contains one independent clause, while a complex sentence has one independent clause at least one independent clause.

4. What Are 5 Examples of Complex Sentences?

Here are five examples of complex sentences for your reference:

1. Because she was late again, she would be docked a day’s pay.

2. If you need help, ask me.

3. He smiled when he saw his best friend.

4. If I won the lottery, I would travel around the world.

5. If I had known about the game, I would have attended.