1. Common Nouns: Common nouns are general names for people, places, things, or ideas. They refer to general categories or objects without specifying any particular one. Examples of common nouns include "computer," "teacher," "city," and "book."
2. Proper Nouns: Proper nouns are specific names given to particular people, places, organizations, or other unique entities. They are capitalized to indicate their specificity. Examples of proper nouns include "John Smith," "London," "Microsoft Corporation," and "World War II."
3. Pronouns: Pronouns are words used to replace nouns or noun phrases in a sentence. They can refer to specific people, places, things, or ideas without naming them directly. Common pronouns include "I," "you," "he," "she," "it," "they," and "we."
Some sources may also include additional categories of nouns, such as collective nouns (referring to groups), abstract nouns (referring to intangible concepts), and concrete nouns (referring to tangible objects). However, the three categories mentioned above are the most commonly recognized and widely used in English grammar.