Grammar for Everyone - Barbara Dykes 2007

Parentheses - brackets and dashes
Introduction
Part II The parts of speech

Definition: This word from Greek para - ’beyond’ and enthesis - ’put in’ means ’added extra’. So in writing it refers to information extra to the main sentence. The sentence is complete without the part in parenthesis. However, the extra part is added to give further information or explanation to that in the main sentence. The extra part is like something just thought of, mid sentence, and as such, has a more abrupt sense than something separated by commas.

Students are reminded that, should they use parenthesis, the parts either side should be grammatically complete without it.

Brackets

Definition: The word ’bracket’ is from French braguette meaning ’a codpiece’, the term for the curved support piece inside men’s breeches.

Brackets indicate a fairly formal division of a sentence, marking off extra information.

For example:

A restaurant called L’Apostrophe in Reims (address on request) ...

Such inverted commas (usually single, rather than double) are understood ...

In her autobiography 'Giving up the Ghost’ (2003), Hilary Mantel reveals .

In addition, we have the formal use of brackets to indicate grouping in algebra.

2 a (4 b + 6) =

Brackets of shapes other than the curve are usually editor’s devices for selected types of additional information.

Dashes

These are generally less formal than other kinds of punctuation and more conversational. Lynne Truss suggests that they are more friendly, as though they are welcoming the extra thought inside as opposed to brackets which imply intrusion.

Dashes are used singly, as a comment added to the end of a sentence, or double for one included within.

For example:

On went the pilgrims through the years - some on foot and some on horseback. They went overseas - to Mexico we think - and were never heard of again.

One dash can lead to a dramatic effect.

For example:

Something floated past the dinghy - it was a human hand!