120 Examples of Irregular Nouns
An irregular noun is a noun that forms its plural in a way that is different from the regular method of adding -s or -es. These nouns often change their vowel sounds or entire spellings when forming plurals.
Here's a list with 120 examples of irregular nouns:
Irregular Nouns with Plural Changes in Vowels or Endings
Alga -> Algae
Analysis -> Analyses
Antenna -> Antennae
Axis -> Axes
Bacterium -> Bacteria
Basis -> Bases
Cactus -> Cacti
Calf -> Calves
Cherub -> Cherubim
Child -> Children
Crisis -> Crises
Criterion -> Criteria
Datum -> Data
Diagnosis -> Diagnoses
Die -> Dice
Dingo -> Dingoes
Ellipsis -> Ellipses
Emphasis -> Emphases
Fungus -> Fungi
Hypothesis -> Hypotheses
Index -> Indices
Knife -> Knives
Leaf -> Leaves
Life -> Lives
Louse -> Lice
Man -> Men
Matrix -> Matrices
Medium -> Media
Memorandum -> Memoranda
Mouse -> Mice
Irregular Nouns with Plural Forms That Remain Unchanged
Bison -> Bison
Cod -> Cod
Deer -> Deer
Fish -> Fish
Grouse -> Grouse
Moose -> Moose
Salmon -> Salmon
Series -> Series
Sheep -> Sheep
Shrimp -> Shrimp
Trout -> Trout
Aircraft -> Aircraft
Barracks -> Barracks
Crossroads -> Crossroads
Headquarters -> Headquarters
Species -> Species
Dice -> Dice
Offspring -> Offspring
Swine -> Swine
Works -> Works
Means -> Means
Scissors -> Scissors
Pants -> Pants
Glasses -> Glasses
Shorts -> Shorts
Trousers -> Trousers
Alms -> Alms
Blues -> Blues
Luggage -> Luggage
News -> News
Irregular Nouns with Unique Plural Forms
Oasis -> Oases
Octopus -> Octopuses/Octopi
Ox -> Oxen
Parenthesis -> Parentheses
Person -> People
Phenomenon -> Phenomena
Radius -> Radii
Self -> Selves
Stimulus -> Stimuli
Syllabus -> Syllabi
Synopses -> Synopses
Thesis -> Theses
Tooth -> Teeth
Vertebra -> Vertebrae
Wife -> Wives
Wolf -> Wolves
Woman -> Women
Alumna -> Alumnae
Amoeba -> Amoebae
Antithesis -> Antitheses
Appendix -> Appendices
Bacillus -> Bacilli
Behalf -> Behalves
Buffalo -> Buffalo
Bureau -> Bureaux/Bureaus
Campus -> Campuses
Chassis -> Chassis
Corps -> Corps
Curriculum -> Curricula
Genus -> Genera
Additional Irregular Nouns
Elf -> Elves
Foot -> Feet
Goose -> Geese
Half -> Halves
Hero -> Heroes
Hoof -> Hooves
Knife -> Knives
Leaf -> Leaves
Life -> Lives
Man -> Men
Mouse -> Mice
Person -> People
Potato -> Potatoes
Scarves -> Scarves
Self -> Selves
Shelf -> Shelves
Thief -> Thieves
Tomato -> Tomatoes
Tooth -> Teeth
Wolf -> Wolves
Woman -> Women
Alumnus -> Alumni
Axis -> Axes
Crisis -> Crises
Diagnosis -> Diagnoses
Ellipsis -> Ellipses
Emphasis -> Emphases
Hypothesis -> Hypotheses
Phenomenon -> Phenomena