Technical terms of Greek and Latin origin – singular and plural forms

SINGULAR

          PLURAL

apparatus

          apparatuses

strategy

          strategies

hierarchy

          hierarchies

appendix

          appendixes/appendices

index

          indexes/indices

gymnasium

          gymnasiums

memorandum

          memoranda

bacterium

          bacteria

criterion

          criteria/criterions

genus

          genera

data

          data

media

          media

phenomenon

          phenomena

analysis

          analyses

oasis

          oases

basis

          bases

hypothesis

          hypotheses

thesis

          theses

crisis

          crises

species

          species

radius

          radii

nucleus

          nuclei

formula

          formulae/formulas