A recent forum question asks about the word data.
The dictionary says the word data can be treated as a singular. But strictly speaking the word is a plural. How does such a thing happen in language? You wouldn’t say, “the cars is fast”. How does a plural gain acceptance as a singular?
The answer is,
A plural gains acceptance as a singular because language is always changing to suit the comfort of the people who speak it.
In the case of data, the singular form datum has been rejected by most English speakers as not sounding right. Hence “data is” and “data are.”
When the study of Latin was standard in the curriculum of English- speaking children, no one thought twice about using datum as the singular form of data. Now that Latin is a rarity in American education, datum sounds foreign and has been abandoned in general usage.
The distinctions between Latin singulars and plurals is still observed for some English words in some contexts–scientific or academic–but for the most part, either the singular or the plural Latin form, depending upon which sounds “less English,” tends to be dropped.
Here are some words that started out with Latin singular and plural forms. In some cases both survive. In others, the plural has been anglicized or taken over as the singular.
Literally “foster daughter” and “foster son,” these words refer in American usage to graduates of an educational institution. Most universities tend to use the masculine forms only. Alumnus is still in use as a singular, but I have heard people use alumni as if it could be either singular or plural.
datum/data In common usage the plural, data, has become accepted as either singular or plural.
medium/media The parts of this pair have taken on different meanings. The plural, media, has come to mean methods of communication such as newspapers, television, radio, and film. Medium can mean the material used by an artist to produce an artistic creation. It can also mean any method for accomplishing something.
Ex. As a reporter, he’s a member of the media.
Which of these mediums do you prefer, watercolor or oil?
By means of what medium do you expect to accomplish this?
And yes, another kind of medium is a person through whom spirits speak.
appendix/appendices The Latin plural is still in use, but one also hears appendixes.
formula/formulae The Latin plural persists in scientific contexts, but one often hears formulas.
encyclopedia/encyclopediae The English plural encyclopedias is more common than the Latin.
index/indices The Latin plural is used in academic contexts, but one commonly hears indexes.
axis/axes I don’t think I’ve ever heard anyone say “axises.” It’s not a word that commonly comes up in conversation.
crisis/crises I have heard “crisises” but in this case the Latin plural crises [cry seez] is easier to say and will probably persist.
criterion/criteria Here is a pair that persists in both the Latin singular and plural. One judges the worth of a book according to a set of criteria. One criterion might be style. Another criterion might be accuracy.
phenomenon/phenomena A tornado is a phenomenon of Nature. Other phenomena are earthquakes, thunderstorms, and floods. Both the singular and plural forms of this word are alive and well.
agendum/agenda Here the singular form has dropped out and people speak of both an agenda and agendas.
memorandum/memoranda Both of these forms are still in use, but I’ve heard memorandums.
cactus/cacti Some people still use the Latin plural, but one hears cactuses.
fungus/fungi[fun dzhai] Both forms are in use, but one also hears funguses.
hippopotamus/hippopotami Since most people now call them hippos, the Latin plural is not much in use. The plural hippopotamuses is a mouthful and when used tends to sound humorous.
Some other unusual singular/plural pairs that may seem to derive from Latin come instead from Greek. They are sometimes mistakenly given invented Latin plurals.
octopus You may hear someone use the plural octopi for this word, but the Latin plural would be octopodes. The English plural is octopuses.
stigma – Here’s a word whose original plural has taken on a different meaning with the result that stigmata and stigmas mean different things.
A stigma is some kind of negative mark. It is usually used figuratively. Ex. In the 1950s a woman was ruined by the stigma of an illegitimate child. The politician was never able to overcome the stigma of having embezzled state funds. The plural of stigma is stigmas.
The original plural stigmata refers to the crucifixion wounds of Christ and to the marks of these wounds as they have appeared on the bodies of certain Christian mystics. Ex. Mystics known to have experienced stigmata include Francis of Assisi and Catherine of Siena.
dogma – The original plural was dogmata, but dogmas has prevailed. The older plural, however, gives us the adjective dogmatic.
There are several other Latin and Greek singular/plural pairs still in use, but these are probably the most common.