When, in the year 400, Saint Jerome gave instructions for punctuating the Latin translation of the Bible that he had just completed, he spoke of divisions ‘per cola et commata’. ‘Commata’ is the plural of ‘comma’, and if the ‘cola’ or colons were the sections of Jerome’s sentences, the ‘commata’ or commas were its subsections. He wanted the Bible’s word to be made clear and unambiguous. He was less concerned with the reading of the text aloud, but instructions for regulating a reader’s breathing were, however, also a matter of colons and commas.
George Puttenham appears to be the first Englishman to use the words ‘comma’ and ‘colon’ as English words. He imported them from Latin, as the Romans had imported them from Greek. In 1592 in The Arte of English Poesie, Puttenham used ‘comma’ and ‘colon’ to mean measures of metrical pause - just as the Ancient Greeks had used them. For the Greeks, the comma was the shortest pause; the colon was twice as long. In music theory, ‘a comma’ still means ‘a minute interval’.
Whether or not they intended their markings to be taken as breathings or parsings, the monks in the centuries succeeding Jerome worked towards ever more efficient ways of presenting their texts. They eventually found that dots were the best punctuation marks for a manuscript, the colon appearing as a dot after a word and the comma as a dot over a word. But the raised dot was not the only way that the monks had of marking their commata. In many manuscripts, the comma appears as a stroke or a slash, a punctuation mark that was given the name ‘virgula’ – a twig, a virgule.
When William Caxton set up his printing press in Westminster in 1476, he chose the virgule, the slash, as his comma sign, very probably because placing a virgule after a word was easier for a printer than placing dot over a word. However, for the next generation of printers, the slash was not an elegant solution. It interrupted the text, and it looked ugly.
In the 1490s, Aldus Manutius of Venice considered the comma question. The full stop had already arrived as the mark to end a sentence so a comma could not simply be a dot on the line, but, by the addition of a tail, Aldus gave the world a punctuation mark that the world has seen fit to keep. Aldus’s comma, sometimes called the ‘semicircular comma’, was a flexible and useful shape.
Venice was recognized as the producing the finest printed books in the world and Manutius recognised as the best printer in Venice. Like his semicolon, his comma gradually spread north from printing shop to printing shop through to Paris and then to London. In the 1520s, English printers began to replace the virgule with the comma. For a time books were printed that mixed commas and virgules on the same page, but the virgule was gradually abandoned as a marker of clauses and phrases. (That left a punctuation mark in need of a job, but not for long; plenty of work would be found for the virgule/slash.)
Today Manutius’s comma appears in various font forms, but it is everywhere in the Western world the sign used to make minor breaks in a text. Less universal are the conventions governing where those breaks should be made. In total there are thirty-nine pages of comma advice in Oxford University Press’s New Hart’s Rules, Cambridge University Press’s Copy-Editing, the American Modern Language Association’s Handbook, and the Chicago University Press’s Manual of Style gives fourteen. All that advice is largely overlapping but not entirely. All is not well with the comma.
A ‘comma-counter’ in American slang is ‘a pedantic person; a pedantic copy editor’, and commas are not widely liked. Mocking remarks made by writers who have no respect for the comma are common. Gertrude Stein said, ‘a comma does nothing but make easy a thing that if you like it enough is easy enough without the comma.’ Lawyers are even more commaphobic than writers. Million-pound lawsuits are periodically fought over commas, and comma placing can have such expensive results that some lawyers protect themselves by stating up front: ‘The headings and punctuation in this agreement are for convenience only and shall be ignored in its interpretation.’
The most august comma dispute involves the Constitution of the United States. Though no one would change a word in the document, printers have felt free over the years to move its commas about. The Constitution’s Second Amendment says, ‘A well regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed.’ Some justices maintain that the wording before the second comma is superfluous. The meaning of the amendment, they say, is contained in the sentence: ‘the right of the people to keep and bear arms, shall not be infringed’. That reading allows every American to carry a gun.
In addition to the arguments raised by its first two commas, the third comma in the Second Amendment raises eyebrows in the twenty-first century. It looks as if it has violated one of the few things on which all the stylebooks are agreed: commas should not break sentences. However, in the eighteenth century, it was not uncommon for a comma to separate subject and predicate. What was good punctuation then is bad indeed now.
More helpful than Gertrude Stein’s mockery and contract lawyers’ caution is Mary Norris’s comma love. Norris joined The New Yorker in 1978, and it took fifteen years for her to rise to the rank of ‘a page O.K.’er - a position that exists only at The New Yorker, where you query proofread pieces and manage them, with the editor, the author, a fact checker, and a second proofreader, until they go to press.’
‘Commas, like nuns, often travel in pairs,’ Mary Norris says. Paired commas serve to subordinate lesser materials and to throw into relief the main subject and predicate of a well-punctuated sentence. To get the full benefit of the idea represented by Norris’ nuns, it is helpful to remember that the ‘kommata’ of Ancient Greek texts were not punctuation marks. They were clauses and phrases. Clauses and phrases can run from the beginning of a sentence to a comma and from a comma to the end of a sentence. The single commas that define initial and terminal clauses and phrases might appear to be traveling alone but they are nun-like; they can form a pair with a capital letter that begins a sentence or a full stop that ends it. With that idea in mind, several kinds of comma can be identified:
adverbial commas: ‘However, I’ll say no more.’
appositive commas: ‘The English Project, an educational charity, does fine work.’
clausal commas: ‘The audience, while I was talking, began looking around.’
phrasal commas: ‘The man, on the platform, had a flushed face.’
quotational commas: ‘Don’t’, he said, ‘say such things.’
salutational commas: ‘Dear Sir,’.
vocative commas: ‘I’m of a mind, Mary, to call it a day’.
As well as coming in pairs, commas come in singles and in multiples, providing useful guides to the eye and pointers to meanings, guides and pointers that greatly speed reading:
conjunctional commas: ‘I rode to the top of the hill, and I rode down again.’
elliptical commas: ‘In Surrey, there are two universities; in Hampshire, four.’
Oxford commas: ‘red, green, blue, and orange spots’.
list commas: ‘red, green, blue and orange spots’.
The Oxford comma is so called because, for over a century, Oxford University Press has required its proofreaders to insert a comma before the ‘and’ introducing the final item in a string of adjectives. (Oxford calls it a serial comma; in America, it is also called the Harvard comma.) The Oxford/Harvard comma differs from the conjunctional comma because that comma with its conjunction comes between two sentences, and it can serve as the equivalent of a full stop. The conjunctional comma preserves the writer from constructions such as ‘I rode to the top of the hill, I rode down again.’ That comma, called a comma splice, is something all the manuals warn against.
Single commas are also used when names are reversed in lists and in indexes. The comma goes between the family name and the given name, so ‘Smith, John’. Single commas are used in dates when the month comes before the day, a format favoured in the United States, so ‘July 4, 1776’. Single commas are used in numbers to demarcate thousands, as in ‘1,000’. That comma is, however, never used in a date, so ‘1776’.
In much of Continental Europe, the comma serves as the decimal marker because the French had early on elected to use the point to make the reading of Roman numbers easier. However, Continental uses of the comma are only indirectly related to English-language punctuation. In the same way, the many uses of the comma in the languages of mathematics and computing are not part of English-language punctuation. However, one software comma might be mentioned. Serial commas are used as separators in word lists, and they are also used as separators in some email address