What is a complex sentence?

Definition: A complex sentence is a sentence that contains an independent clause and one or more dependent clauses. An independent clause, also known as a main clause, can stand alone as a complete sentence, expressing a complete thought.

They often use subordinating conjunctions like because, since, or until, etc. to connect clauses.

According to the Oxford Learner’s Dictionary, “A complex sentence contains one main part (main clause of a sentence) and one or more other parts (called affixes or subordinate clauses).”.

According to the Collins Dictionary, a complex sentence is defined as “a sentence containing at least one main clause and one subordinate clause.”

According to The Macmillan Dictionary, “a complex sentence consisting of an independent clause and one or more subordinate clauses.”

Example of a complex sentence:

• I saw a dog which was lying on the road.
• I gave him a camera which was very cheap.
• This is the school where I was taught in my childhood.
• The man, who stole my watch was caught. 
• If the path is beautiful, let us not ask where it leads.
• If you work hard, you will get success definitely.

What is the most common type of complex sentence?

One of the most common types of complex sentences is conditional sentences, which discuss imaginary situations, often using an if-then structure. In conditional sentences, one clause is true only if both clauses are true.

Example: If I were a bird. I will fly in the sky.

How to form a complex sentence?

We use independent and dependent clause to combine the complex sentence. Here is the process to combine the complex sentences.

Step 1: Firstly we start with an independent clause:

Example: She went to America.

Step 2: Then we use a dependent Clause.

Example: Because she wants to study further.

Step 3: Now add both sentences.

Example: She went to America because she wanted to study further.

When do you use commas?

• If the dependent clause comes first, place a comma between it.
• If the independent clause comes first, no comma is needed.

Example 1: She went to America because he wanted to study further.

Example 2: Because he wanted to study further, she went to America.

The most common subordinating conjunction used in complex sentences:

• after
• although
• as
• because
• before
• even though
• if
• once
• since
• so long as
• though
• unless
• until
• when
• whenever
• whereas
• wherever
• while

Complex Sentence Structure:

There is no fixed structure, but here are some structures that we can use to form complex sentences.

Structure 1: Independent Clause + Subordinating Conjunction + Dependent Clause.

Structure 2: Subordinating Conjunction + Dependent Clause + Comma (,) + Independent Clause.

Examples:

• My dog was hungry even though she already had breakfast.
• Even though she already had breakfast, my dog was hungry.
• When I grow up, I want to be an astronaut

More Examples of Complex Sentences:

1. I waited for Ram Gopal till he arrived.
2. He had left home before he came.
3. He came where she was sitting.
4. Nehru was welcomed wherever he went.
5. I do not know the time when my brother will come from Delhi.
6. A thief who came to my house was caught by then police .
7. Ramesh who belongs to a good family is a good boy.
8. The messenger had to perform a duty which was difficult.
9. I saw a dog which was lying on the road.
10. I gave him a camera which was very cheap.
11. This is the school where I was taught in my childhood.
12. The man, who stole my watch was caught.
13. If you had invited me, I would have attended the party.
14. This is the school where I study.
15. I know Seema whose father is a mechanic.