knife
knives
self
selves
offspring
offspring
scarf
scarves
tooth
teeth
analysis
analyses
leaf
leaves
bacterium
bacteria
radius
radii
vertebra
vertebrae
deer
deer
antenna
antennae
appendix
appendices
index
indeces
cactus
cacti
louse
lice
man
men
foot
feet
hypothesis
hypotheses
wife
wives
aircraft
aircraft
oasis
oases
matrix
matrices
half
halves
woman
women
life
lives
salmon
salmon
fungus
fungi
species
species
moose
moose
loaf
loaves
quiz
quizzes
alumnus
alumni
child
children
fish
fish
axis
axes
nucleus
nuclei
mouse
mice
elf
elves
ox
oxen
sheep
sheep
thesis
theses
phenomenon
phenomena
formula
formulae
medium
media
person
people
die
dice
wolf
wolves
series
series
goose
geese