Types of Sentences (Structure-wise)

A sentence can consist of one clause (independent clause) or more than one clause (independent and dependent clauses). The independent clause is also known as a main clause. The dependent clause is also known as a subordinate clause.

Different sentences have different structures. There are four types of sentences depending upon its structure or formation (the numbers of clauses in the sentence).

  Simple Sentence

A simple sentence comprises only one clause (main or independent clause). A main clause has both the subject and the verb and expresses a complete meaning. Hence, a simple sentence is simply a main-clause. It has no dependent clause.


I bought a chair.
He ate a mango.
She goes to college.
They are laughing.

  Compound Sentence

A compound sentence has at least two main (or independent) clauses connected by coordinating conjunctions. It has no dependent clause.

The coordinating conjunctions, used to join main clauses, are “and, for, nor, but, so, yet, or”.  Independent clauses are also sometime connected by a semicolon (;) mark. A comma may not or may be used before a conjunction in a compound sentence.


I wrote him a letter but he didn’t reply me.
I told him about his failure in the exam and he became sad.
She failed many times yet she is not disappointed.
I needed help; he helped me.

  Complex Sentence

A complex sentence has one main-clause (independent clause) and at least one subordinate-clause (dependent clause) connected by subordinate conjunctions such as ‘although, because, since, unless, when’ or a relative pronoun such as ‘who, that, which etc’.

In the following examples, the underlined part of each sentence is a main clause while the remaining part is a subordinate (dependent) clause.


I saw a man who was wearing a white shirt.
The girl bought a doll which sings a song.
She gifted me a book that has a great knowledge.
We helped a child who was crying.

Note. If the complex sentence starts with the independent (or main) clause, a comma will not be used between clauses in the complex sentence. But if the complex sentence starts with a dependent (or subordinate) clause then the comma will be used after the dependent clause in the complex sentence. Read the examples given below.

It is quite hot today although it is raining.
Although it is raining, it is quite hot today.

  Complex-Compound Sentence

A complex-compound sentence has at least two main (independent) clause and one or more subordinate (dependent) clauses. It can also be called compound-complex sentence.

In the following examples, the underlined parts represent main clause while the non-underlined parts represent subordinate clause.


I like Physic, but my friend likes Biology who wants to become a doctor.
I waited for him, but he didn’t come which disappointed me.
She bought a green shirt and I bought brown shirt which looks very decent.