| Noun type |
Forming the plural |
Examples |
| Ends with -fe |
Change f to v
then
Add -s |
knife - knives
life - lives
wife - wives |
| Ends with -f |
Change f to v
then
Add -es |
half - halves
wolf - wolves
loaf - loaves |
| Ends with -o |
Add -es |
potato - potatoes
tomato - tomatoes
volcano - volcanoes |
| ends with -us |
Change -us to -i |
cactus - cacti
nucleus - nuclei
focus - foci |
| ends with -is |
Change -is to -es |
analysis - analyses
crisis - crises
thesis - theses |
| ends with -on |
Change -on to -a |
phenomenon - phenomena
criterion - criteria |
| ALL KINDS |
Change the vowel
or
Change the word
or
Add a different ending |
man - men
foot - feet
child - children
person - people
tooth - teeth
mouse - mice |
| Unchanging |
Singular and plural
are the same |
sheep
deer
fish (sometimes) |
