Appendix A – Spelling rules for -s endings on regular nouns
Rules
For nouns that end in a vowel + y, add -s.
For nouns that end in a vowel + o, add -s.
For nouns that end in -s, -ss, -sh, -ch, or -x, add -es.
For nouns that end in a consonant + o, add -es.
For nouns that end in a consonant + y,
change the y to i and add -es.
For nouns that end in -f or -fe,
change the -f to v and add -{e)s.
For most other nouns, add -s.
Examples
boy
boys
day
days
toy
toys
way
ways
radio
radios
zoo
zoos
bus
buses
business
businesses
class
classes
brush
brushes
match
matches
box
boxes
potato
potatoes
tomato
tomatoes
activity
activities
body
bodies
city
cities
company
companies
country
countries
dictionary
dictionaries
party
parties
leaf
leaves
life
lives
wife
wives
book
books
car
cars
pencil
pencils