1. Pluralization: This is the most common change.
* Regular Plurals: Add "s" to the singular form (e.g., cat - cats, book - books)
* Irregular Plurals: These have unique forms (e.g., child - children, mouse - mice, ox - oxen)
2. Possessive Case: This indicates ownership or possession.
* Singular Possessive: Add "'s" to the singular noun (e.g., dog's bone, Mary's book)
* Plural Possessive: Add "'s" to irregular plurals ending in "s" (e.g., children's toys) or just an apostrophe to regular plurals (e.g., cats' food)
3. Gender: Some nouns change based on gender.
* Masculine vs. Feminine: Actor - Actress, King - Queen, Prince - Princess
* Neuter: This category often doesn't change (e.g., house, car)
4. Number: Some nouns have different forms for singular and plural, even if they don't follow the regular plural rules.
* Singular vs. Plural: One person - two people, one sheep - two sheep
5. Compound Nouns: These are formed by combining two or more words. The base words may change to indicate function.
* Modifying Nouns: A "bookcase" is a case for books, not a case that is a book.
* Combining Nouns: A "toothbrush" is a brush for teeth, not a brush that is a tooth.
6. Irregular Forms: There are many nouns that have irregular forms, often historical in origin.
* Irregular Nouns: Foot - feet, tooth - teeth, goose - geese
Example:
The dog (singular, base form) chased the ball (singular, base form).
The dogs (plural form) chased the balls (plural form).
The dog's (possessive form) tail was wagging.
The children's (plural possessive) toys were scattered across the floor.
It's important to note that not all nouns change form in all these ways. For instance, some nouns don't have a plural form (e.g., furniture, advice). However, understanding how nouns change can help you use them correctly in your writing and speaking.