Discuss all parts of speech explicitly.

Parts of speech are categories of words that describe their function and meaning within a sentence. The main parts of speech are:

1. Nouns: Words that represent a person, place, thing, or idea (e.g., dog, city, happiness).
2. Pronouns: Words that replace nouns (e.g., he, she, it, they, we).
3. Verbs: Words that describe an action, occurrence, or state of being (e.g., run, is, think).
4. Adjectives: Words that modify or describe nouns and pronouns (e.g., big, red, happy).
5. Adverbs: Words that modify verbs, adjectives, or other adverbs, often indicating manner, time, place, or degree (e.g., quickly, yesterday, very).
6. Prepositions: Words that show the relationship between a noun or pronoun and other words in the sentence, often indicating position or direction (e.g., on, in, under, to).
7. Conjunctions: Words that connect words, phrases, or clauses (e.g., and, but, or).
8. Interjections: Words or short phrases that express strong emotion and are often grammatically separate from the rest of the sentence (e.g., Wow!, Ouch!).