Some Irregular plurals.

abyss abysses

alumnus alumni

analysis analyses

aquarium aquaria

arch arches

atlas atlases

axe axes

baby babies

bacterium bacteria

batch batches

beach beaches

brush brushes

bus buses

calf calves

chateau chateaux

cherry cherries

child children

church churches

circus circuses

city cities

cod cod

copy copies

crisis crises

curriculum curricula

deer deer

dictionary dictionaries

domino dominoes

dwarf dwarves

echo echoes

elf elves

emphasis emphases

family families

fax faxes

fish fish

flush flushes

fly flies

foot feet

fungus fungi

half halves

hero heroes

hippopotamus hippopotami

hoax hoaxes

hoof hooves

index indexes

iris irises

kiss kisses

knife knives

lady ladies

leaf leaves

life lives

loaf loaves

man men

mango mangoes

memorandum memoranda

mess messes

moose moose

motto mottoes

mouse mice

nanny nannies

neurosis neuroses

nucleus nuclei

oasis oases

octopus octopi

party parties

pass passes

penny pennies

person people

plateau plateaux

poppy poppies

potato potatoes

quiz quizzes

reflex reflexes

runner-up runners-up

scarf scarves

scratch scratches

series series

sheaf sheaves

sheep sheep

shelf shelves

son-in-law sons-in-law

species species

splash splashes

spy spies

stitch stitches

story stories

syllabus syllabi

tax taxes

thesis theses

thief thieves

tomato tomatoes

tooth teeth

tornado tornadoes

try tries

volcano volcanoes

waltz waltzes

wash washes

watch watches

wharf wharves

wife wives

woman women