100 Irregular Plural Nouns in English
The vast majority of English nouns make their plural by adding either -s (books, bands, bells) or -es (boxes, bunches, batches). These plural forms follow a regular pattern.
100 Irregular Plural Nouns List
| addendum | addenda or addendums |
| aircraft | aircraft |
| alumna | alumnae |
| alumnus | alumni |
| analysis | analyses |
| antenna | antennae or antennas |
| antithesis | antitheses |
| apex | apices or apexes |
| appendix | appendices or appendixes |
| axis | axes |
| bacillus | bacilli |
| bacterium | bacteria |
| basis | bases |
| beau | beaux or beaus |
| bison | bison |
| bureau | bureaux or bureaus |
| cactus | cacti or cactus or cactuses |
| château | châteaux or châteaus |
| child | children |
| codex | codices |
| concerto | concerti or concertos |
| corpus | corpora |
| crisis | crises |
| criterion | criteria or criterions |
| curriculum | curricula or curriculums |
| datum | data |
| deer | deer or deers |
| diagnosis | diagnoses |
| die | dice or dies |
| dwarf | dwarves or dwarfs |
| ellipsis | ellipses |
| erratum | errata |
| faux pas | faux pas |
| fez | fezzes or fezes |
| fish | fish or fishes |
| focus | foci or focuses |
| foot | feet or foot |
| formula | formulae or formulas |
| fungus | fungi or funguses |
| genus | genera or genuses |
| goose | geese |
| graffito | graffiti |
| grouse | grouse or grouses |
| half | halves |
| hoof | hooves or hoofs |
| hypothesis | hypotheses |
| index | indices or indexes |
| larva | larvae or larvas |
| libretto | libretti or librettos |
| loaf | loaves |
| locus | loci |
| louse | lice |
| man | men |
| matrix | matrices or matrixes |
| medium | media or mediums |
| memorandum | memoranda or memorandums |
| minutia | minutiae |
| moose | moose |
| mouse | mice |
| nebula | nebulae or nebulas |
| nucleus | nuclei or nucleuses |
| oasis | oases |
| offspring | offspring or offsprings |
| opus | opera or opuses |
| ovum | ova |
| ox | oxen or ox |
| parenthesis | parentheses |
| phenomenon | phenomena or phenomenons |
| phylum | phyla |
| quiz | quizzes |
| radius | radii or radiuses |
| referendum | referenda or referendums |
| salmon | salmon or salmons |
| scarf | scarves or scarfs |
| self | selves |
| series | series |
| sheep | sheep |
| shrimp | shrimp or shrimps |
| species | species |
| stimulus | stimuli |
| stratum | strata |
| swine | swine |
| syllabus | syllabi or syllabuses |
| symposium | symposia or symposiums |
| synopsis | synopses |
| tableau | tableaux or tableaus |
| thesis | theses |
| thief | thieves |
| tooth | teeth |
| trout | trout or trouts |
| tuna | tuna or tunas |
| vertebra | vertebrae or vertebras |
| vertex | vertices or vertexes |
| vita | vitae |
| vortex | vortices or vortexes |
| wharf | wharves or wharfs |
| wife | wives |
| wolf | wolves |
| woman | Women |
