- Latin plurals
- Latin pluralsPlurals of Latin words used in English are formed according to the rules either of the source language (apex/apices, stratum/strata) or of the borrowing language (gymnasium/gymnasiums, arena/arenas). In some cases more than one form is in use, sometimes with a usage distinction (appendix/appendices/appendixes, formula/formulae/formulas) and sometimes with no clear distinction (cactus/cacti/cactuses). Words ending in -is usually follow the original Latin form (basis/bases, crisis/crises) for reasons of euphony, and the same rule operates in other cases (nucleus/nuclei). A more alien form is the plural -mata of words ending in -ma in the singular (lemma/lemmata, stigma/stigmata). There are occasional surprises; for example we might expect the plural of crux to be (Latin) cruces but it is in fact more often (English) cruxes. There is a trap for the unwary with Latinate nouns ending in -us which cannot form plurals in -i for formal grammatical reasons: hiatus (a fourth-declension noun in Latin with a plural hiatus), ignoramus (a first-person plural verb in Latin, not a noun), octopus (a Romanized form of a Greek word octopous), vademecum (cum being a preposition meaning ‘with’). The table below shows the types of plural that the more commonly used Latin words have in English; when there is more than one both are shown:singular form / Latin-type plural / English pluraladdendum / addendaalga / algaeapex / apices / apexesappendix / appendices / appendixesaquarium / aquaria / aquariumsarena / / arenasautomaton / automata / automatonsbasis / basescactus / cacti / cactusescodex / codicescompendium / compendia / compendiumscorrigendum / corrigendacrematorium / crematoria / crematoriumscrisis / crisescrux / cruces / cruxesdesideratum / desiderataencomium / encomia / encomiumsfocus / foci / focusesformula / formulae / formulasgenus / generagymnasium / gymnasia / gymnasiumshelix / helices / helixesindex / indices / indexeslemma / lemmata / lemmasmatrix / matrices / matrixesmaximum / maxima / maximumsmemorandum / memoranda / memorandumsmiasma / miasmataminimum / minima / minimumsmomentum / momenta / momentumsmoratorium / / moratoriumsnucleus / nucleioasis / oasesradix / radicesreferendum / referenda / referendumsstigma / stigmata / stigmasstratum / stratathesis / thesesvortex / vortices / vortexesFurther information will be found in the separate entries for some of these words
Modern English usage. 2014.