Introduction
Although most nouns have plurals formed according to regular rules (see Regular Plurals of Nouns), some nouns have unusual, or irregular plurals. This page will introduce the most common ones, so that you can learn them.
Types of irregular plural
There are many types of irregular plural, but these are the most common:
Noun type | Forming the plural | Example |
---|---|---|
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) |
When you are sure that you understand the lesson, you can continue with the exercises.