Types of Sentences (Based on Structure)

Sentences are classified based on their structure. A sentence may contain one or more clauses. A clause is a group of words with a subject and a verb that can stand alone as a complete sentence, e.g., He is sleeping in the room. In this example 'He is sleeping' can be seen as a clause becaue it can stand alone as a complete sentence giving a complete meaning on its own. However, 'in the room' here can be seen as a phrase because it does not consist of a subject and verb, and cannot stand alone as a complete sentence.

When a sentence has more than one clause, at least one clause is the main (independent) clause, while the others are subordinate (dependent) clauses. The main clause can stand alone and convey a complete meaning, whereas the subordinate clause cannot and relies on the main clause to make sense.

Example.

 I saw a man who was laughing.

In this example, there are two clauses: (I saw a man) and (who was laughing). The first clause is the main clause and can stand alone as a complete sentence. The second clause is subordinate and cannot stand alone, as it depends on the main clause for meaning.

Based on the number and type of clauses, sentences can be divided into four types:

  Simple Sentence

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

Examples:

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

  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, or which.

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

Examples:

• 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 either the main clause or the subordinate clause. If it starts with the main clause, a comma is not used between the clauses. But if it starts with the subordinate clause, a comma must be used after the subordinate clause.

• 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 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 (;). A comma may or may not be used before the coordinating conjunction in a compound sentence.

Examples.

• 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-Compound Sentence

A complex-compound sentence has at least two main (independent) clauses and at least one 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 the sentences represent the main clauses, whereas the red part represents the subordinate clause.

Examples.

• 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.