Here you will find our ESL activities and worksheets on irregular plural nouns. We are currently designing all new content and will post more worksheets as we create them. You can create a free account and we will update you when we release more content.
Recap
Irregular plural nouns are nouns that, unlike most nouns in English, cannot be converted to their plural form simply by suffixing with s or es.
Here is a list of the most common irregular nouns in English:
| Singular | Plural |
| 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 |
