A compound sentence has two or more coordinate clauses (i.e., independent clauses of equal rank) joined together by a coordinating conjunction.

Study the following examples carefully:

The night is dark and I am far from home.

First coordinate clause: The night is dark
Second coordinate clause: I am far from home
Conjunction: and

I laugh, I run, I leap, I sing for joy. (4 coordinate clauses)

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

1.    Cumulative

A cumulative conjunction simply adds one clause to another. Examples are: and, as well as, not only…but also, nor etc.

He is a fool and you are a bigger fool.
He is a writer and a thinker too.
Smoking is injurious to the health of the smoker as well as those around him.
Winston Churchill was not only a politician but also a great writer.
He cannot speak nor can he hear. (Note the inverted word order in the clause ‘can he hear’.)

2.    Alternative

An alternative conjunction presents two alternatives before us.
Examples are: either…or, neither…nor, otherwise, or else etc.

You should neither borrow nor lend.
You can have either tea or coffee.
You must submit the report now, otherwise you will be punished.
Come away from the window, or else they will see you.

3.    Adversative

We use an adversative conjunction to draw a contrast between two facts. Examples are: but, still, yet, whereas etc.

He is lazy whereas his brother is very hard working.
She is beautiful but not intelligent.
I tried my best, still I couldn’t solve the problem.
He is rich, yet he looks miserable.

4.    Illative

An illative conjunction draws an inference from a statement or fact. Examples are: so, therefore, for etc.

He has influence, so he may get a verdict in his favor.
He may see your point for he is a reasonable man.
He took things easy, naturally he couldn’t pass the examination.
The two angles are equal, therefore the opposite angles must be equal.