Tricky & Irregular Plurals
From cactus/cacti to child/children — 202 English nouns whose plural form doesn't just add -s.
- addendum
- adieu
- aircraft
- alumna
- alumnus
- analysis
- annex
- antenna
- apex
- appendix
- aquarium
- army
- atlas
- attorney-general
- avocado
- axis
- baby
- bacterium
- batch
- beach
- beau
- belief
- bison
- box
- boy
- brother-in-law
- brush
- buffalo
- bureau
- bus
- buzz
- cactus
- cafe
- calf
- cargo
- census
- chateau
- cherry
- chief
- child
- church
- city
- class
- cliff
- codex
- commander-in-chief
- complex
- corpus
- cortex
- country
- court-martial
- crisis
- criterion
- crossroads
- cul-de-sac
- curriculum
- datum
- day
- deer
- diagnosis
- die
- dish
- dress
- duplex
- dwarf
- echo
- editor-in-chief
- elf
- ellipsis
- embargo
- family
- fax
- fish
- fly
- focus
- foot
- formula
- forum
- fox
- fungus
- gas
- genus
- glass
- goose
- gulf
- gymnasium
- half
- halo
- handkerchief
- headquarters
- hero
- hoax
- hoof
- hypothesis
- index
- iris
- key
- kiss
- knife
- lady
- larva
- leaf
- lens
- life
- loaf
- louse
- man
- match
- matrix
- means
- medium
- memo
- memorandum
- millennium
- mongoose
- monkey
- monsieur
- moose
- mosquito
- moth
- mother-in-law
- mouse
- museum
- nebula
- notary-public
- nucleus
- oasis
- octopus
- offspring
- ox
- parenthesis
- party
- passerby
- peach
- penny
- person
- phenomenon
- photo
- piano
- plateau
- platypus
- potato
- puppy
- quiz
- radio
- radius
- reef
- referendum
- rhinoceros
- roof
- runner-up
- salmon
- sandwich
- scarf
- self
- series
- sheep
- shelf
- silo
- sky
- species
- spectrum
- spy
- stadium
- stimulus
- story
- stratum
- studio
- swine
- syllabus
- symposium
- synopsis
- tableau
- tax
- tempo
- thesis
- thief
- tomato
- tooth
- topaz
- tornado
- torpedo
- toy
- trout
- ultimatum
- valley
- vertebra
- vertex
- veto
- video
- virus
- volcano
- vortex
- waltz
- watch
- wharf
- wife
- wish
- witch
- wolf
- woman
- zero