Breaking Down Number Inflected Nouns

Do you ever get confused about whether to write mouse or mice? Don’t worry, you’re not alone! It’s important to understand how nouns change depending on if there’s one or more of them.

Get ready to dive into noun number inflection and make it as easy as pie.

In studying the inflection of nouns and pronouns, we have to consider gender, number, person, and case.


Gender is how we categorize people based on their sex. We show gender, whether it’s masculine, feminine, or neutral, by the noun’s meaning or by the pronouns we use with it (like ‘he’, ‘she’, or ‘they’).


Numbers help us know if a word is about one or many things (like one dog, two dogs)


Person tells us if the nouns refer to
1. the speaker,
2. the person being talked to, or
3. the person or thing being talked about.

You can usually figure out who it’s talking about from the context, pronouns, and verb choice.


Nouns change case to show their relationship to verbs, prepositions, or another noun. (like ‘the dog’s bone’ showing possession).

We’re talking about number inflected nouns in this blog.

What is Number Inflection?

Number inflection in grammar is just a fancy way of saying how a noun changes to show if it’s talking about one thing or more than one which are the only two options.

The singular number denotes but one person, place, or thing. The plural number denotes more than one person, place, or thing.

Plurals of Singular Nouns

The following rules are used to form plurals of singular nouns.

1. Most nouns add ‘s’ or ‘es’ to the singular.

♦ boy, boys
♦ stove, stoves
♦ bench, benches

2. Nouns ending in ‘x’, ‘s’, ‘ss’, ‘ch’, ‘sh’, or ‘x’, add ‘es’ to the singular.

♦ fox, foxes
♦ wish, wishes
♦ glass, glasses
♦ coach, coaches
♦ buzz, buzzes

3. Nouns ending in y preceded by a vowel (a, e, i, o, u) add ‘s’.

♦ valley, valleys
♦ soliloquy, soliloquies
♦ colloquy, colloquies

Most proper names ending in ‘y’, take the plural of ‘s’
♦ Rowley, Rowleys
♦ Mary, Marys
♦ Murphy, Murphys

4. When ‘y’ is preceded by a consonant (any letter other than a vowel), ‘y’ is changed to ‘i’ and ‘es’ is added.

♦ army, armies
♦ pony, ponies
♦ sky, skies

5. Most nouns ending in ‘f’ or ‘fe’ add ‘s’.

♦ Scarf, scarfs
♦ safe, safes.

A few change ‘f’ or ‘fe’ to ‘v’ and add ‘es’.

♦ wife, wives
♦ self, selves
♦ wolf, wolves

Some others are beef, calf, elf, half, leaf, loaf, sheaf, shelf, staff, thief, life.

6. Most nouns ending in ‘o’ add ‘s’.

♦ cameo, cameos
♦ folio, folios
♦ piano, pianos

Several nouns ending in ‘o’ are preceded by a consonant add ‘es’.

♦ volcano, volcanoes
♦ hero, heroes
♦ potato, potatoes

The most important of the latter class are: buffalo, cargo, calico, echo, embargo, flamingo, hero, motto, mulatto, potato, tomato, tornado, torpedo, veto.

7. Letters, figures, characters, etc., add the apostrophe and s (‘s).

♦ 6’s, c’s, t’s, #’s.

Irregular Noun Inflection

The English language likes to throw curveballs. Some nouns change in a way that doesn’t follow the usual pattern.

♦ child becomes children
♦ mouse becomes mice

These are called irregular inflections, and they can be a bit of a brainteaser.

For instance, why do we say ‘feet’ instead of ‘foots’ when talking about more than one foot.

Or consider ‘person’ and ‘people’.

And don’t forget ‘tooth’ and ‘teeth’, ‘man’ and ‘men’, ‘woman’ and ‘women’.

The list goes on with ‘goose’ turning into ‘geese’, ‘ox’ into ‘oxen’, and ‘louse’ into ‘lice’.

These irregular forms don’t have a one-size-fits-all rule, which can be confusing

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Special Cases in Number Inflection

Then there are the special cases. Some nouns stay the same in both singular and plural forms,

♦ sheep
♦ species
♦ Japanese

Plurals with Two Meanings

A few nouns have two plurals, but usually with some difference in meaning.

♦ brother
brothers (relatives)
brethren (members of the same society)

♦ horse
horses (animals)
horse (cavalry)

♦ foot
feet (parts of the body)
foot (infantry)

♦ sail
sails (on vessels)
sail (vessels in a fleet)

♦ head
heads (in usual sense)
head (of cattle)

♦ fish
fishes (individually)
fish (collectively)

♦ cloth
cloths (pieces of cloth)
clothes (garments)

♦ die
dies (for stamping)
dice (for gaming)

Compound Nouns

The last part of compound nouns usually gets an ‘s’ when you make them plural.

♦ spoonful, spoonfuls
♦ boathouse, boathouses

Non English Plurals

Others, especially those borrowed from other languages, follow different rules and keep their non-english plurals, Some of the common ones include. (think ‘cactus’ to ‘cacti’).

This shift reflects a broader move towards more inclusive and nondiscriminatory language in our society.


Singular Plural
 analysis  analyses
antithesis antitheses
appendix appendices
axis axes
bacillus bacilli
bacterium bacteria
basis bases
cactus cacti
crisis crises
curriculum curricula
datum data
ellipsis ellipses
erratum errata
formula formulæ
genius genii
genus genera
gymnasium gymnasia
hippopotamus hippopotami
hypothesis hypotheses
larva larvæ
memorandum memoranda
nebula nebulæ
oasis oases
parenthesis parentheses
phenomenon phenomena
radius radii
species species
stratum strata
synopsis synopses
tableau tableaux
tempo tempi
terminus termini
thesis theses
vertebra vertebrae


Nouns that are Only Plurals

Certain nouns are only plural.

♦ athletics
♦ billiards
♦ dregs
♦ nuptials
♦ oats
♦ scissors
♦ shears
♦ suds
♦ tweezers
♦ tongs
♦ trousers
♦ vitals

Plurals with Singular Meanings

A few nouns are plural in form, but singular in meaning.

♦ gallows
♦ news
♦ measles
♦ mumps
♦ small pox
♦ politics

Plus, some sciences

♦ economics
♦ ethics
♦ mathematics
♦ physics

The Role of Context in Number Inflection

Context plays a huge role in how we use nouns. Depending on what you want to say, the form of a noun can change, often based on whether you’re referring to one thing or many.

♦ The fish are swimming (refers to multiple fish)
♦ The fish is fresh (refers to just one)

Contextual cues aren’t always about counting, though

♦ My glasses are broken. (refers to one set of eyeglasses)
♦ The glasses are on the table. (refers to more than one drinking glass.)

Another interesting case is with the word ‘data’.

♦ The data are conclusive. (In scientific contexts, ‘data’ is treated as plural)
♦ The data is clear  (In everyday use, it’s commonly used as a singular noun)

Context can affect other forms of a word.

♦ I read a book (uses ‘read’ pronounced as ‘red’, implying past tense)
♦ I will read a book pronounces ‘read’ as ‘reed’, showing future or present tense.

The spelling doesn’t change, but the pronunciation and meaning do, all thanks to context.

Understanding the situation you’re writing about is key because it helps you choose the right noun form.

Exercises for Number Inflected Nouns

Take a few moment and see if you know the plurals for these words.

  1. Book
  2. Fox
  3. Child
  4. Loaf
  5. Butterfly
  6. Tooth
  7. Lady
  8. Mouse
  9. City
  10. Cactus
  11. Puppy
  12. Leaf
  13. Goose
  14. Man
  15. Woman
  16. Hero
  17. Ox
  18. Potato
  19. Knife
  20. Foot
Click on the + button for the answers
  1. Book – Books
  2. Fox – Foxes
  3. Child – Children
  4. Loaf – Loaves
  5. Butterfly – Butterflies
  6. Tooth – Teeth
  7. Lady – Ladies
  8. Mouse – Mice
  9. City – Cities
  10. Cactus – Cacti
  11. Puppy – Puppies
  12. Leaf – Leaves
  13. Goose – Geese
  14. Man – Men
  15. Woman – Women
  16. Hero – Heroes
  17. Ox – Oxen
  18. Potato – Potatoes
  19. Knife – Knives
  20. Foot – Feet

10 Tips for Number-Inflected Nouns

1. Identify Irregular Nouns: Familiarize yourself with common irregular nouns (like ‘child’ to ‘children’).
2. Watch for Exceptions: Remember exceptions to the rules, like ‘mouse’ to ‘mice’ and ‘goose’ to ‘geese’.
3. Use a Dictionary: Don’t hesitate to look up a noun’s plural form if you’re unsure.
4. Understand Context: Pay attention to how the context affects the noun form (singular vs. plural).
5. Non-English Origin Nouns: Learn plural forms of nouns derived from other languages, like ‘cactus’ to ‘cacti’.
6. Collective Nouns: Be aware of collective nouns that can take singular or plural verbs based on their meaning in the sentence.

7. Consistency is Key: Be consistent in using singular or plural forms within a sentence or paragraph.
8. Editing and Proofreading: Always recheck your work for correct noun forms.
9. Use Writing Tools: Grammar checking tools can help identify incorrect noun inflection.
10. Understand Compound Nouns: Learn how to pluralize compound nouns (like ‘mother-in-law’ to ‘mothers-in-law’).

Last Words on Number-Inflected Nouns

The way we use gender in language is changing, and as writers, we have the power to shape and influence this change. By understanding and thoughtfully using gender inflection in nouns, we can create more inclusive, realistic, and engaging narratives.

Happy writing!



Feature Image by Gerd Altmann from Pixabay.



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