Aside from cliché phrases like carpe diem (“seize the day”), or shortened forms like i.e. and e.g., (which, by the way, are very common in English), there are also regular words and nouns which follow distinct Latinate patterns.
Latin noun patterns in English
Nouns in English that use their original Latinate forms are trickier for English speakers (and learners) to remember because they don’t follow typical English plural noun rules. Most nouns in English simply add ‘s’ or ‘es’ to denote a plural (e.g., dog/dogs, table/tables).
Latin nouns, however, use their own singular and plural endings, of which there are a few notable patterns. We can remember their correct singular and plural forms by recognizing the suffixes these nouns use.
Words ending in “-ex” / “-ix” to “-ices”
A common singular noun ending is “-ix” and “-ex”, which converts to “-ices” as a plural. Over time, and likely from the frequent misuse of the original Latin forms, these words have come to adopt a regular English noun form by adding “-es”. One is not more correct than the other; however, some reserve certain spellings to a particular definition (so be sure to check that the spelling you use is correct in the context).
- matrix ⇨ matrices or matrixes
- vortex ⇨ vortices or vortexes
- vertex ⇨ vertices or vertexes
- index ⇨ indices or indexes
- appendix ⇨ appendices or appendixes
- apex ⇨ apices or apexes
- codex ⇨ codices or codexes
Words ending in “-us” / “-i”
Same as the group of words above, these nouns have also come to use a standard English noun form as well (in addition to their original Latin forms).
Though, by and large, most nouns that are Latin and end in “-us” will switch to “-i” as a plural. However, this is not invariably true, since words like “virus“, “platypus” and even “octopus” now reluctantly use the “-i” ending as a plural (platypus and octopus both being originally Greek). We would not, however, say “viri” as a plural for “virus” (it’s just viruses).
- cactus ⇨ cacti or cactuses
- syllabus ⇨ syllabi or syllabuses
- alumnus ⇨ alumni or alumnus’s
- fungus ⇨ fungi or funguses
- radius ⇨ radi or radiuses
- stimulus ⇨ stimuli or stimuluses
- nucleus ⇨ nuclei or nucleuses
- hippopotamus ⇨ hippopotami or hippopotamuses
Words ending in “-on” / “-um” to “-a”
Interestingly, words like “media”, “criteria” and “bacteria” are all plural forms, which are for the most part used exclusively (relative to their singular noun counterparts). It’s uncommon to hear “bacterium” or “datum”, except perhaps in scientific or academic writing.
Also, like the previous groups, these words likewise retain their original Latin form but have also come to accept an English standard form as well.
- phenomenon ⇨ phenomena or phenomenons
- criterion ⇨ criteria
- bacterium ⇨ bacteria
- datum ⇨ data
- medium ⇨ media
- addendum ⇨ addenda or addendums
- colloquium ⇨ colloquia or colloquiums
- referendum ⇨ referenda or referendums
- memorandum ⇨ memoranda or memorandums
- curriculum ⇨ curricula or curriculums
- erratum ⇨ errata or erratums
- symposium ⇨ symposia or symposiums
- stratum ⇨ strata or stratums
- spectrum ⇨ spectra or spectrums
Words ending in “-a” / “-ae”
- formula ⇨ formulae or formulas
- vertebra ⇨ vertebrae or vertebras
- larva ⇨ larvae or larvas
- nebula ⇨ nebulae or nebulas
- antenna ⇨ antennae or antennas
“Antenna” prefers antennae as a plural to refer to an insect appendage, and antennas to refer to a television’s antenna
