A quick and simple guide to the comma

The comma (,) is a tricky little creature, often peppering texts when an inexperienced author panics about their punctuation. Used correctly, commas should clarify the meaning of the texts by dividing and grouping words, phrases or clauses to help the reader. But the definition of the comma is not easy.

Originally a slash (rather like those used in transcriptions of song lyrics) to denote a pause for breath, its modern form was first used by Aldus Pius Manatius in fifteenth-century Italy.

Its name (taken from the Greek komma, “a piece cut off”) first defined the clause itself before it was understood as referring to the little apostrophe-like mark that sits on the baseline of the text.

Commas are far more widely used than other clause-dividers such as colons (:) and semi-colons (;), but are sometimes used too often or appear in random positions in a sentence as people are unsure how they should organise their words.

The use of commas to separate clauses seems to be a particularly stubborn headache.

It does not help with comma definition that they are used slightly differently in different languages and even in different conventions within the same language. In British English, for example, some writers are expected to place the comma outside quotation marks when reporting direct speech; others expect them to be included.

Some authors use the Oxford comma (also called the serial comma) when writing lists to avoid confusion between different items; others prefer their lists without.

However, there are several comma functions that are broadly the same across all versions of English.

Occasions when to use a comma include:

• in lists (e.g., “inverted commas, commas, semi-colons and full stops”)
• in direct speech, when using inverted commas (e.g., “However comma”, he dictated)
• to separate clauses
• to act as a marker to show parenthetical phrases (e.g., “Comma definition, often written about, is important for good writing”)
• with “However”
• as vocative commas (e.g., “I hope, Chris, you’re using your vocative commas correctly”)

There are few words that act like magnets for comma trouble: for example, whether the comma comes before or after but in sentence; or if a However comma is always required.