You can thank Middle English for this one. Middle English, spoken between 1150 to 1500, made the singular noun plural, as "childre." Childre became "children." Our modern-day singular noun, "child," continues to be made plural with an "en" -- "children," like "brethren" or "oxen."
An easy way to remember this one? From the movie, "Elf," "elves try to stick to the four main food groups: candy, candy canes, candy corns, and syrup." Elves, an irregular noun, is pluralized with a "ves" -- although we can't confirm the diet.
You need to add more than just an "s" to the end of an irregular noun such as potato. To make this root vegetable plural, add an "es" to the end: potatoes.
The conventional way of making a word plural -- with an "s" or an "es" -- doesn't apply to some nouns. Some nouns require spelling changes, like "foot" to "feet," or "man" to "men," or "woman," which becomes, "women."
Generally, if a noun ends in "s," "sh," "ch," "x" or "z," you add an "es" to the end of the word and that's it. Box plays by this rule, and its plural is boxes.
"Tooth" has what's considered an irregular noun plural. It's not tooths or toothes. Rather, it changes to "teeth."
In the English language there are always exceptions, but the general rule for making a word ending in "us" plural is to change the "us" into an "i." And "alumnus" follows that rule, ending up as "alumni."
Just like "focus," "fungus" and "octopus," cactus is made plural without an "s" or "es." To pluralize cactus, you do it with an "i" -- "cacti." You could probably get away with adding an "es" to form "cactuses," mostly because a lot of people won't know any better!
Reflexive pronouns like "yourself" end in "self." To make them plural, the end is changed to "selves."
You could say, "deers," but it's pretty rare, and most people will think you're wrong. The most acceptable plural for the irregular noun "deer" is, "deer."
The English word "millennium" is derived from Latin, and pluralizing it follows the typical English grammar rule of swapping the "um" at the end of the word with an "a" -- going from "millennium" to "millennia." Before the 1930s, "millenniums" was the popular plural form, but in 21st-century language, "millennia" is preferred.
Whether you're talking about the insect or your flight, "fly" is a tricky one to pluralize. It's true; it's "flies, without the "y."
The plural of "fish" is, most of the time, "fish." But sometimes, "fishes" is acceptable, such as when you're talking about more than one species.
Although many of us are guilty of using "data" as both singular and plural, "data" is actually the plural form of "datum."
When asked where they are, you might say something like, "the scissors are in the drawer." Because "scissors" has no singular form, plural verb agreement is used ("scissors are").
Often if you don't know the plural, adding an "s" or an "es" will do. But sometimes, there really isn't a rule; you just need to know. Person, for instance, is changed to "people" to make it plural.
Sometimes making a noun plural means changing a few vowels or letters. For instance, mouse, ending in "ouse" gets changed to "ice" -- and the plural of mouse is mice.
To make the singular noun, "die," plural, it requires a little more than adding an "s." Here, "die" is the singular form of "dice," not dies or dyes.
A lot of people get this wrong, using "bacteria" as both the singular and the plural noun. It's not. It's actually the plural form, of the noun "bacterium."
If you get this noun's singular and plural forms mixed up, you're not alone. "Phenomenon" is the singular noun. And "phenomena," the plural.
Rooves, which rhymes with hooves, was popular in spoken English long ago. Today, "roofs" is the commonly-used plural form of "roof."
Imagine you've been diagnosed with two conditions, such as asthma and hayfever. These are your "diagnoses," the plural form of "diagnosis.
Just like other English nouns that end in "is," prognosis is pluralized by changing the "is" to an "es." The plural of prognosis, then, is "prognoses"
Sometimes a noun -- like jeans, goggles or music -- is both its own singular and plural forms. Salmon, too.
As a general rule, you'd never use an apostrophe to form the plural of a noun -- or an acronym, like ATM. Apostrophes can be used with plural nouns, but they're used to indicate possession.
Don't make a faux pas! There is no differene between the singular and plural form of this French phrase.
Pluralizing this word, from the Latin for "smallness," requires more than an "s" or "es." Although we speak English, many of our words are from the Latin language. Here we use the Latin plural for the singular noun, minutia: minutiae.
Just like almost all words (there are always exceptions!) ending in "is," making "hypothesis" into a plural known requires swapping the "is" with "es." And that's it.
Runner-up is a noun and an adverb/preposition. Knowing only nouns can be pluralized -- "runner" is the noun -- the plural of runner-up becomes, "runners-up."
The plural of hippopotamus is "hippopotami," if you stick to the traditional grammar rule of pluralizing a noun ending in "us" by changing that "us" into an "i." But in our modern American English, it's become more acceptable to use an "es," calling a group of hippopotami, "hippopotamuses." Or, you could just skip all that and call them "hippos."
If your house is on a cul-de-sac, there may be other culs-de-sac in your neighborhood. Just like other phrases such as notaries public and mothers-in-law, a noun followed by a modifier (usually, but not always, an adjective) is pluralized by making the noun (cul, notary, mother) plural, even though it's the first word.
In American English, to make a noun that ends in "is" plural, you change the "is" to "es," such as nemesis and nemeses or thesis and theses.
"Economics" is a plural noun when it's used in relation to a set of conditions, such as the economics of a project. It's also, when it's being used to refer to the social science of economics, considered a singular noun.
Although "index" is a noun ending in an "x," it takes more than adding an "es" to the end to make it plural. "Index" is irregular, and it's spelling is changed in its plural form, "indices."
Château and its common plural form, châteaux, are pronounced the same although they're spelled differently. Châteaus, too, is acceptable, but not the first choice.
When you have more than one of something, you'd use a plural noun to describe it -- but it's not always as simple as adding an "s" to the end of the word. (Although, sometimes it is.) See if you can correctly guess which plural matches with singular noun.
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