A virgule is a forward slash used in three contexts in modern English. It is represented on the page by a ‘/’ symbol. The first function of the virgule is to separate alternatives in a sentence. The second is to replace ‘per’ in a sentence as with speeds. It is also used to separate lines of continuous verse.
The word virgule came to English from the French word ‘virgule’ with the same spelling. It originates from the classical Latin word ‘virgula’ meaning literally ‘little twig,’ but used to mean ‘punctuation.’ The root word of virgula is virga, meaning rod, twig or stick. The word was first used in English in 1837.
The slash was first used in Ancient Rome and can be found in both its literature and its inscriptions across the Roman Empire. Medieval manuscripts used the slash as a modern comma. Two concurrent virgules or // were used originally as dashes or –. They were later tipped horizontally to make the modern equals sign or =.
In modern English, the term virgule is only used with reference to English writing and punctuation. The forward slash is used in many other contexts including computers, math and Internet coding or markup language. When used in these contexts, it is called a ‘slash,’ or another term is used.
Virgules are used as alternatives to separate a pair of options when the answer is not known. Sometimes, this can be used for more than two options, but this is rare. Common examples used in English include ‘either/or’ and ‘and/or.’ It is used on answer sheets in surveys and school worksheets to separate a pair of answers such as ‘yes/no’ and ‘true/false.’
‘Per’ is replaced with the virgule in order to shorten a sentence and to provide a kind of abbreviation. A common 'per' replacement used in English concerns speeds. For example, miles per hour is replaced with miles/hour. As an alternative to the virgule, English speakers can use abbreviations such as mph instead of miles per hour.
Some poems are written in continuous verse. This means there are theoretical breaks between lines of verse, but when written, these lines are not cut and placed below one another, but continue along the page like lines of prose. The virgule in this context tells the reader when the end of a line is reached. They are also used in Anglo-Saxon and Norse poetry sometimes to separate half-lines.
Modern English has seen an irregular use of the virgule. While it is strictly limited to the three forms mentioned above, some English speakers use the virgule to separate two letter initialisms. Examples of this additional usage include w/o instead of without and o/o instead of over-operator.