Irregular plural nouns are special because they don’t just add -s or -es. Instead, they change their spelling in unique ways to show that there is more than one.
Common Irregular Plurals
Here are some groups of irregular plurals and examples in each group.
| Pattern | Example Singular | Example Plural |
|---|---|---|
| Change vowel (usually −f/−fe to −ves) | wolf | wolves |
| Change vowel (usually o to oes) | hero | heroes |
| Change internal vowel | man | men |
| Change ending from −us to −i | cactus | cacti |
| Change ending from −is to −es | analysis | analyses |
| Change ending from −on to −a | phenomenon | phenomena |
| Same singular and plural | sheep | sheep |
| Add −ren | child | children |
What is the correct irregular plural of 'phenomenon'?
phenomena
'Phenomenon' changes the ending from -on to -a to form 'phenomena'.
Usage Tips
- Always use irregular plurals for more than one.
- Don’t add extra −s to irregular plurals.
- Some words have both regular and irregular plurals (e.g., “formula” → “formulas” or “formulae”).
- Use the irregular plural form that matches the style you want (scientific, formal, or everyday).
Practice
Convert these singular nouns to their correct irregular plural form.
| Singular | Plural |
|---|---|
| leaf | leaves |
| foot | feet |
| cactus | cacti |
| child | children |
| mouse | mice |
Summary
Irregular plurals are nouns that change form to show more than one. Learn the common patterns and practice to get them right.
What is the best way to learn irregular plurals?
Learn the common patterns and practice to get them right.
Recognizing patterns and practicing helps you master irregular plurals.
Last updated: Wed Jun 18, 2025
