Sentence is the largest structural unit of a language. Sentences can be divided into three basic categories depending on its grammatical structure, i.e. the position and requirement of subject, verb etc.

1. Simple Sentence
2. Complex Sentence and
3. Compound Sentence

Simple Sentence

 A simple sentence has one main clause. It has only one subject and one finite verb.

He is an artist.

In this sentence ‘he’ is the only subject, and ‘is’ the only finite verb.

( Finite verb – a verb that changes with person, number and tense. )

I like cars.                                              I like to drive cars.

She likes cars.                                      She likes to drive cars.

(I Like – He likes – finite verb)           (to drive – non finite verb)

Complex sentence

A sentence containing one main clause and one or more subordinate clauses is called a complex sentence.

They rested when evening came.

As the boxers advanced into the ring, the people said that they would not allow them to fight.

The people said. (main clause)

As the boxers advanced into the ring. (subordinate clause)

That they would not allow them to fight. (subordinate clause)

We may add more subordinate clauses (dependent clause) to make it more complex.

Adding  1 subordinate clause to the main clause.

Ronny went to school, though he did not want to.

Adding  2 subordinate clauses to the main clause.

Though Ronny went to school, he did not want to go, as he had not done his homework.

Adding  3 subordinate clauses to the main clause.

Though Ronny went to school, he did not want to go, as he had not done his homework and he will get punished.

Compound Sentence

A compound sentence contains two main clauses or independent clauses joined by a co-ordinating linker or conjunction.

He tried hard but he did not succeed.

This sentence consists of two independent clauses joined by a conjunction.

He tried hard. ( but)

He did not succeed.

Night came on and rain fell heavily and we all got wet.

This sentence consists of three independent clauses joined by conjunctions.

Night came on. (and)

Rain fell heavily. (and)

We all got wet.

Complex Compound

A complex- compound sentence contains one main clause and two or more subordinate clause that are connected with a co-ordinating linker.

The man said    that three workers had arrived   and    that four others were absent.

The man said                                   -(main clause)

 that three workers had arrived     – (subordinate clause)

 and                                                     -(co-ordinating linker)

 that four others were absent.        – (subordinate clause.)

One main clause and two subordinating clauses joined by a linker.

Compound complex

A compound complex sentence contains two main clauses, in which one main clause has a sub-clause.

The Maths syllabus is difficult  and  since it was implemented years ago,  many students have failed.

The Maths syllabus is difficult    -(main clause)

 And                                                   – (co-ordinating linker)

 since it was implemented years ago, – (subordinate clause)

many students have failed.                 – (main clause)

Examples of the five types of sentences based on structure.

Simple –  He loves books.

Compound – He loves books and he often buys books.

Complex – He loves books which are interesting.

Complex compound – He loves books which are interesting and (which) have a lot of information.

Compound complex – He loves books but as they are expensive he buys them rarely.