§ 3. With detached members of the sentence either a comma or a dash is used.

1. To separate a loose apposition a comma or a dash is used. The latter is less common.

He, Martin Eden, was a better man than that fellow. (London)

The old gentleman, her father, was always dabbling in specula­tion. (Thackeray)

To think that Johnnie — my best friend — should have acted so meanly. (Bennett)

2. To separate all types of detached adverbial modifiers a comma is used.

The Chuzzlewit family was, in the very earliest times, closely con­nected with agricultural interest. (Dickens) It being then just dinner-time, we went first into the great kitchen. (Dickens)

Away went George, his nerves quivering with excitement at the news so long looked for. (Thackeray)

Mr. Micawber sat in his elbow-chair, with his eyebrows raised. (Dickens)

Old Jolyon had risen, and, cigar in mouth, went to inspect the group. (Galsworthy)

He drew his hands away, shivering. (Voynich)

Poor Jemima trotted off, exceedingly flurried and nervous. (Thackeray)

The people, seeing my empty carriage, would rush for it. (Jer­ome)

3. To separate detached attributes a comma is used.

There are some truths, cold, bitter, tainting truths. (Dickens)

Here we have a remark, at once consistent, clear, natural. (Dick­ens)

4. To separate detached objects a comma is used.

Maggie, with a large book on her lap, shook her heavy hair. (Eliot)

But instead of the print, he seemed to see his wife. (Galswor­thy)

Sometimes a dash is used.

§ 4. To separate parenthetical words, groups of words, and clauses a comma, a dash, or brackets may be used. The comma is the most usual.

To occupy her mind, however, she took the jobs given her. (Galsworthy)

In fact, she marked the change in his face with satisfaction. (London)

As for my mother, both her brothers were policemen. (Lindsay)

She sang a foolish song of Gustave Charpentier's — a song born dead — and she sang it sentimentally. (Bennett)

To the hired butler (for Roger only kept maids) she spoke about the wine. (Galsworthy)

§ 5. To separate interjections a comma or an exclamation mark may be used.

Oh, Doreen didn't know anything about it. (Cusack)

Ah! That's the way to make the money. (Cusack)

§ 6. To separate direct address a comma is used.

Arthur, have you thought what you are saying? (Voynich)

And run in to see me, my lad, when you have time any evening.(Voynich)

Note.lt should be borne in mind that a comma (or a colon) and not an exclamation mark is used in salutation in letters.

My dear Jon, we have been here now a fortnight. (Galsworthy)

The Compound Sentence

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

§ 7. Coordinate clauses joined asyndetically are always separated by a punctuation mark.

The most usual punctuation mark 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)