Plurals of Foreign Nouns
These nouns have irregular plural forms. They often make their plurals according to the rules of the language they were taken from (e.g. Latin or Greek) and an English plural spelling. Always use a good dictionary when using foreign plurals. Here are some examples.
1. Words of Latin origin
| Singular | Latin plural | English plural |
|---|---|---|
| antenna | antennae | antennas |
| appendix | appendices | appendixes |
| cactus | cacti | cactuses |
| curriculum | curricula | curriculums |
| formula | formulae | formulas |
| index | indices | indexes |
| millennium | millennia | millenniums |
| referendum | referenda | referendums |
| stadium | stadia | stadiums |
| terminus | termini | analyses |
| thesaurus | thesauri | thesauruses |
| vortex | vortices | vortexes |
2. Words of Greek origin
Nouns which end in -is usually come from Greek. Their plurals are made by changing the -is to -es:
| Singular | Plural |
|---|---|
| analysis | analyses |
| axis | axes |
| basis | bases |
| crisis | crises |
| diagnosis | diagnoses |
| neurosis | neuroses |
| thesis | theses |