1. Content Words: These words carry the main meaning of a sentence. They are also known as open-class words, because we can constantly add new words to this category.
* Nouns: People, places, things, and ideas (e.g., cat, school, table, freedom)
* Verbs: Actions or states of being (e.g., run, think, exist)
* Adjectives: Describe nouns (e.g., big, blue, happy)
* Adverbs: Describe verbs, adjectives, or other adverbs (e.g., quickly, very, really)
2. Function Words: These words connect and organize content words, but don't carry much meaning themselves. They are also known as closed-class words, because we don't add new words to this category very often.
* Prepositions: Show relationships between words (e.g., on, in, to, from)
* Conjunctions: Connect words, phrases, or clauses (e.g., and, but, or, because)
* Determiners: Specify nouns (e.g., a, the, this, that)
* Pronouns: Replace nouns (e.g., I, you, he, she, it, we, they)
* Auxiliary verbs: Help main verbs (e.g., have, do, be, will, would, can, could)
Remember, this is a general categorization. There are some exceptions and overlaps, and some words can function in multiple ways depending on the context.