Spelling worksheet focusing on irregular plural nouns, designed for educational practice.

Let's solve this step by step.

The task is to find the singular form of each irregular plural noun listed. Irregular plural nouns do not follow the standard rule of adding "-s" or "-es" to form the plural. Instead, they have unique singular forms that must be memorized or researched.

Here are the plural words given, and we'll find their corresponding singular forms:

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1. feet → foot *(Given as an example)*
2. men → man
3. children → child
4. teeth → tooth
5. geese → goose
6. women → woman
7. mice → mouse
8. fungi → fungus
9. oxen → ox
10. people → person
11. dice → die
12. octopi → octopus *(Note: "octopi" is a common but technically incorrect plural; correct plural is "octopuses" or "octopi" from Latin root. But in this context, "octopus" is the singular.)*
13. deer → deer *(Same in singular and plural)*
14. sheep → sheep *(Same in singular and plural)*
15. cacti → cactus
16. fish → fish *(Same in singular and plural, though "fishes" can be used for different species)*
17. moose → moose *(Same in singular and plural)*
18. lice → louse
19. indices → index
20. larvae → larva

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Final Answer (Fill in the blanks):

| 1. Example: foot | 11. die |
|------------------|--------|
| 2. man | 12. octopus |
| 3. child | 13. deer |
| 4. tooth | 14. sheep |
| 5. goose | 15. cactus |
| 6. woman | 16. fish |
| 7. mouse | 17. moose |
| 8. fungus | 18. louse |
| 9. ox | 19. index |
| 10. person | 20. larva |

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Explanation:

- Many irregular plurals come from Old English or Latin roots.
- Some nouns (like *deer*, *sheep*, *moose*) are the same in both singular and plural.
- Others change spelling significantly (e.g., *children* from *child*, *geese* from *goose*).
- Latin-derived words like *fungi*, *indices*, and *larvae* often use Latin plural forms, so their singulars are based on Latin roots.

This exercise helps students learn and recognize common irregular plural forms in English.