A compound sentence consists of two or more principal clauses joined together by a coordinating conjunction. A compound sentence may also include one or more subordinate clauses.

The coordinating clauses of a compound sentence can be joined by four kinds of coordinating conjunctions.

Cumulative

These conjunctions simply add one clause to another.

He is a fool and you are a bigger fool.
God made the country and man made the town.
He was not only a great politician but also a great orator.
He can’t speak, neither can he hear.

Alternative

These conjunctions place two alternatives before us.

He is either a fool or a rogue.
You should neither borrow nor lend.
You must obey my instructions, otherwise you will be dismissed.

Adversative
These conjunctions draw a contrast between two facts.

He is slow but he is steady.
I tried my best, nevertheless I failed.
He is rich, yet he is unhappy.

Illative
These conjunctions draw an inference from a statement or fact.

He is diligent, therefore he will succeed.
He may be able to see your point for he is a reasonable man.
He has influence, so he may be able to win the case.

Shortened forms of the compound sentence

Omission of the conjunction

The conjunction is not always present in a compound sentence.

I came, I saw, I conquered.
I laugh, I run, I leap, I sing for joy.

Omission of the subject
When the clauses have a common subject, we may omit it in the second clause.

The horse neighed and pawed the ground.

Omission of the predicate (when the clauses have a common predicate)

One threw a tomato and another an egg. (= One threw a tomato and another threw an egg.)