Do You Know the 35 Hardest Plurals in the English Language?

By: Becky
Estimated Completion Time
1 min
Do You Know the 35 Hardest Plurals in the English Language?
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About This Quiz

Are you a grammar expert? Does the misuse of plurals on the internet drive you nuts? If you think you know more than the average Joe about the plural forms of common, and some uncommon, words, take this quiz to prove your knowledge.

The easiest way to make a word plural is to add an "s." But that doesn't work for every word. Some other rules of plurals include adding an "es" to words that end in "x," "ch," "s,: or an "s-like" sound; add an "ies" and drop the "y" for a word that ends in "y;" and add a "ves" and drop the "f" or the "fe" for words that end in "f" or "fe." But some words don't play by the rules. For instance, if the plural forms of potato and tomato are tomatoes and potatoes, then why isn't the plural of the word memo "memoes" (it's memos)? And some words don't have plural forms at all. For instance, the plural of moose is moose, the plural of fish is fish, and the plural of deer is deer. If you're not confused, then this might just be the quiz for you.

Let's find out how much you really know about irregular plurals.

Tooth
Teefers
Teeth
Tooths
Correct Answer
Wrong Answer

Teeth is the plural of tooth. We thought we'd start with something easy.

Person
People
Personses
Person's
Correct Answer
Wrong Answer

People is the plural of person. What rule does this follow?!

Criterion
Criterions
Criteria
Criteriones
Correct Answer
Wrong Answer

The plural of criterion is criteria. We think most people have more trouble with the singular form of this one.

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Human
Humen
Humans
Humens
Correct Answer
Wrong Answer

The plural of human is humans. But if the plural of woman is "women," and the plural of man is "men," then why isn't the plural of human "humen"?

Memo
Memoes
Memose
Memos
Correct Answer
Wrong Answer

The plural of memo is memos. Hey wait ... aren't we supposed to add an "es" to words ending in "o"?

Species
Specy
Specees
Species
Correct Answer
Wrong Answer

The plural of species is species. In some, very rare, instances, the word "specie" is used as the singular form.

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Ox
Oxen
Oxes
Ox's
Correct Answer
Wrong Answer

The plural of ox is oxen. Does that mean that the plural of box is "boxen"? Sigh.

Potato
Potatoes
Potatos
Potaties
Correct Answer
Wrong Answer

The plural of potato is potatoes. Similarly, the plural of tomato is tomatoes. But remember, never spell tomato "tomatoe." That's just wrong.

datum
Datums
Datumies
Data
Correct Answer
Wrong Answer

The plural of datum is data. We know what data is, but who knew that the singular form was "datum"?

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Elf
Elves
Elfs
Elfses
Correct Answer
Wrong Answer

The plural of elf is elves. Similarly, the plural of self is "selves."

Radius
Radiuses
Radii
Radius'
Correct Answer
Wrong Answer

Radii is the plural of radius. Well, that's not confusing at all.

Crisis
Crises
Crisis'
Crisis's
Correct Answer
Wrong Answer

Crises is the plural of crisis. For many words that end in "us," change the "us" to an "i" to make it plural.

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Roof
Roofs
Rooves
Roofes
Correct Answer
Wrong Answer

The plural of roof is roofs. But if the plural of knife is knives, why isn't the plural of roof "rooves"? We're so confused!

Syllabus
Syllabi
Syllabies
Syllabus'
Correct Answer
Wrong Answer

Syllabi is the plural of syllabus. A syllabus is an outline, usually of a course.

Kennedy
Kennedys
Kennedies
Kennedai
Correct Answer
Wrong Answer

The plural of Kennedy is Kennedys. The rule "change the y to an i and add es" does not apply to proper nouns.

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Scissors
Scissors
Scissor
Scissorses
Correct Answer
Wrong Answer

The plural of scissors is scissors. Similarly, the plural of shorts is shorts.

Hoax
Hoaxes
Hoaxs
Hoaxii
Correct Answer
Wrong Answer

The plural of hoax is hoaxes. Nope, that's not a hoax.

Die
Dice
Dies
Dices
Correct Answer
Wrong Answer

The plural of die is dice. This is another one where the singular form is more misunderstood than the plural form.

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Millennium
Millennia
Millenniums
Millennias
Correct Answer
Wrong Answer

The plural of millennium is millennia. Add an "l" and you're talking about a generation: millennial.

Phenomenon
Phenomenons
Phenomena
Phenomenai
Correct Answer
Wrong Answer

The plural of phenomenon is phenomena. Similarly, the plural of automaton is "automata."

Tableau
Tableaux
Tableaus
Tableies
Correct Answer
Wrong Answer

The plural of tableau is tableaux. Similarly, the plural of chateau is chateaux.

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Diagnosis
Diagnosises
Diagnosis'
Diagnoses
Correct Answer
Wrong Answer

Diagnoses is the plural of diagnosis. Similarly, analyses is the plural of analysis.

Cod
Cod
Cods
Codes
Correct Answer
Wrong Answer

The plural of cod is cod. Like deer and hair, cod is the same in both the singular and the plural forms.

Moose
Moose
Meese
Mooses
Correct Answer
Wrong Answer

The plural of moose is moose. Well, that's not confusing at all.

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Stylus
Stylus'
Stylai
Styli
Correct Answer
Wrong Answer

The plural of stylus is styli. Sometimes the word "styluses" is used for the plural.

Hippopotamus
Hippopotamuses
Hippopotami
Hippopotamies
Correct Answer
Wrong Answer

The plural of hippopotamus is hippopotami. Similarly, the plural of rhinoceros is rhinoceri.

Cul-de-sac
Culs-de-sac
Cul-de-sacsis
Cul-de-saci
Correct Answer
Wrong Answer

The plural of cul-de-sac is culs-de-sac. Similarly, the plural of brother-in-law is brothers-in-law.

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Passerby
Passersby
Passerbies
Passerbys
Correct Answer
Wrong Answer

The plural of passerby is passersby. We think that goes against the rules.

Census
Censai
Census'
Censuses
Correct Answer
Wrong Answer

The plural of census is censuses. No, it's not censai.

Axis
Axis'
Axeis
Axes
Correct Answer
Wrong Answer

The plural of axis is axes. Yup, the plural of axis is the same as the plural of axe.

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Cello
Celloes
Celloses
Celli
Correct Answer
Wrong Answer

The plural of cello is celli. But why isn't it "celloes"?

Schema
Schemata
Schemas
Schemies
Correct Answer
Wrong Answer

The plural of schema is schemata. A schema is a pattern or structure.

Mongoose
Mongeese
Mongooses
Mongeise
Correct Answer
Wrong Answer

The plural of mongoose is mongooses. Wait, shouldn't it be mongeese?

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Aquarium
Aquaria
Aquariums
Aquariumes
Correct Answer
Wrong Answer

The plural of aquarium is aquaria. We had to double check this one.

Index
Indices
Indexes
Index'
Correct Answer
Wrong Answer

Indices is the plural of index. Huh? This is just one of those you have to memorize.

You Got:
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