Most nouns are made plural by adding -s or -es. However, some nouns also change other letters when adding the -s to become plural.
Words with an -f sound at the end become plural by changing the -f to a -v before adding -s.
wife becomes wives
knife becomes knives
leaf becomes leaves
thief becomes thieves
calf becomes calves
half becomes halves
loaf becomes loaves
self becomes selves
shelf becomes shelves
wolf becomes wolves
Words ending in -us become plural by changing to end with an -i
syllabus becomes syllabi
stimulus becomes stimuli
fungus becomes fungi
Words ending in -is change to -es when becoming plural.
basis becomes bases
axis becomes axes
crisis becomes crises
oasis becomes oases
Certain words change letters when becoming plural. It is best to memorize the spelling of these irregular plural nouns.
▶It’s your turn. Find the noun in the first sentence that should be changed to plural to fit into the blank of the second sentence. Yesterday I bought a loaf of bread. I already had bread, so now I have two ______. Did you figure out which plural noun goes into the blank? Good for you!