English has many irregular nouns that form their plurals by changing a vowel, not just by adding “-s” or “-es”. These patterns can be confusing for learners because the spelling and pronunciation shift at the same time. On this page, you’ll find a clear, easy-to-scan table with two columns: singular and plural. Each pair shows how the vowel changes from one form to the other, with common everyday examples like “man/men” and “tooth/teeth”. Use this list to review, practice, or build vocabulary, and to make your speaking and writing more natural and accurate.
| Singular | Plural |
|---|---|
| analysis | analyses |
| axis | axes |
| basis | bases |
| child | children |
| crisis | crises |
| criterion | criteria |
| diagnosis | diagnoses |
| die | dice |
| dormouse | dormice |
| foot | feet |
| goose | geese |
| index | indices |
| louse | lice |
| man | men |
| matrix | matrices |
| mouse | mice |
| neurosis | neuroses |
| nucleus | nuclei |
| parenthesis | parentheses |
| person | people |
| phenomenon | phenomena |
| radius | radii |
| stimulus | stimuli |
| syllabus | syllabi |
| thesis | theses |
| tooth | teeth |
| woman | women |
