The compound sentence and the complex sentence

THE COMPOUND SENTENCE

To separate coordinate clauses the following rules on the use of stops are observed.

Coordinate clauses joined asyndetically are always separated by a stop.

The most usual stop is the semicolon.

Arthur looked at his watch; it was nine o’clock. (Voynich)

The policeman took no notice of them; his feet were planted apart on the strip

of crimson carpet stretched across the pavement; his face, under the helmet,

wore the same stolid, watching look as theirs. (Galsworthy)

A colon or a dash may be used when the second coordinate clause serves to explain the first. They serve to express the relations which a conjunction would express.

Breakfast over, Aunt Polly had family worship: it began with a prayer built

from the ground up of solid courses of scriptural quotations. (Twain)

Ellsworth advised a triangular piano — the square shapes were so

inexpressibly wearisome to the initiated. (Dreiser)

A comma is used to separate coordinate clauses when the connection between them is very close.

A fly settled on his hair, his breathing sounded heavy in the drowsy silence,

his upper lip under the white moustache puffed in and out. (Galsworthy)