IRREGULAR PLURALS LIST
Study these groups of words to learn how they change to plural.
Each group of words has similar changes.
US -> I
| SINGULAR | PLURAL |
| alumnus | alumni |
| cactus | cacti |
| focus | foci/focuses |
| fungus | fungi/funguses |
| nucleus | nuclei |
| radius | radii |
| stimulus | stimuli |
IS -> ES
| SINGULAR | PLURAL |
| axis | axes |
| analysis | analyses |
| basis | bases |
| crisis | crises |
| diagnosis | diagnoses |
| ellipsis | ellipses |
| hypothesis | hypotheses |
| oasis | oases |
| paralysis | paralyses |
| parenthesis | parentheses |
| synthesis | syntheses |
| synopsis | synopses |
| thesis | theses |
IX -> ICES
| SINGULAR | PLURAL |
| appendix | appendices |
| index | indeces/indexes |
| matrix | matrices/matrixes |
EAU -> EAUX
| SINGULAR | PLURAL |
| beau | beaux |
| bureau | bureaus/bureaux |
| tableau | tableaux/tableaus |
*** -> EN
| SINGULAR | PLURAL |
| child | children |
| man | men |
| ox | oxen |
| woman | women |
*** -> A
| SINGULAR | PLURAL |
| bacterium | bacteria |
| corpus | corpora |
| criterion | criteria |
| curriculum | curricula |
| datum | data |
| genus | genera |
| medium | media |
| memorandum | memoranda |
| phenomenon | phenomena |
| stratum | strata |
NO CHANGE
| SINGULAR | PLURAL |
| deer | deer |
| fish | fish |
| means | means |
| offspring | offspring |
| series | series |
| sheep | sheep |
| species | species |
OO -> EE
| SINGULAR | PLURAL |
| foot | feet |
| goose | geese |
| tooth | teeth |
A -> AE
| SINGULAR | PLURAL |
| antenna | antennae/antennas |
| formula | formulae/formulas |
| nebula | nebulae |
| vertebra | vertebrae |
| vita | vitae |
OUSE -> ICE
| SINGULAR | PLURAL |
| louse | lice |
| mouse | mice |