Types of Sentences (Structure-wise)

A sentence can consist of one clause or more than one clause. A clause is a group of words including a subject and an object and thus, can stand alone as a simple sentence. However, a sentence may also include more than one clause where at least one clause is the main (or independent) clause, and the other clauses include subordinate (or dependent) clauses. The main (or independent) clause can stand alone as a sentence to give a complete meaning. However, the subordinate (dependent) clause cannot stand alone as a sentence because it is dependent on the main clause to give complete meaning.


 I saw a man who was laughing.

The above example has two clauses (I saw a man) and (who was laughing). The first clause (I saw a man) is the main (or independent) clause and can stand alone as a complete sentence. However, the second clause (who was laughing) is a subordinate (or dependent) clause because it depends on the main clause to give complete meaning and cannot stand alone as a complete and meaningful sentence.

Depending on the number of clauses (in a sentence), a sentence can have different structures which are generally divided into the following four types.

  Simple Sentence

A simple sentence has only one clause (main or independent clause). Since the main clause has both the subject and the verb, it expresses a complete meaning. Therefore, a single main clause can be called a simple sentence. It is simply one main clause and has no dependent clause.


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

  Compound Sentence

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

The coordinating conjunctions, used to join the main clauses, are and, for, nor, but, so, yet, or’.  These clauses are also sometimes joined by using a semicolon mark (;). A comma may or may not be used before the coordinating conjunction in a compound sentence.


  • I wrote him a letter, but he didn’t reply to me.
  • I told him about his failure in the exam and he became sad.
  • She failed many times, yet she is not disappointed.
  • The patient took his medicine so he can recover from the illness.
  • I am sorry for I did not help you.
  • I needed his 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 subordinating conjunctions such as ‘although, because, since, unless, when’ or a relative pronoun such as ‘who, that, which, etc.’.

In the following examples, the blue part of each sentence is the main clause whereas the red part is a subordinate (dependent) clause.


  • I saw a man who was wearing a red shirt.
  • The girl bought a doll which sings a song.
  • She gifted me a book that helped me in preparation for my exam.
  • We helped a child who was crying.
  • We saw a joker who was playing the guitar.

A complex sentence can start with the main clause as well as the subordinate clause. However, if it starts with the main clause, a comma is not used between the clauses in the sentence. But if it starts with the subordinate clause, a comma must be used after the subordinate clause in the sentence. See the following examples.

  • It is quite hot today although it is raining.
  • Although it is raining, it is quite hot today.
  • You cannot succeed unless you work sincerely.
  • Unless you work sincerely, you cannot succeed.

  Complex-Compound Sentence

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

Each of the following examples has two main clauses and one subordinate clause. The blue parts of sentences represent the main clauses whereas the red part represents a subordinate clause.


  • I like Physics, but my friend likes Biology who wants to become a doctor.
  • I waited for him, but he did not come which disappointed me.
  • He bought a red shirt, but I bought a white shirt which was cheaper.
  • The cat ran after a mouse and the mouse hid under the table which was made of wood.
  • We helped a boy, and the boy became happy which made us happy too.
  • He discussed his arm pain with a doctor, and the doctor advised him to take medicine which relieved his pain.