1. Common Nouns: These nouns refer to general people, places, things or ideas. For example: book, car, teacher, city.
2. Proper Nouns: These nouns refer to specific people, places, things or ideas. Proper nouns are always capitalized. For example: John, London, Google, Taj Mahal.
3. Pronouns: These are nouns that take the place of a noun or noun phrase. For example: he, she, it, they, we.