The eight parts of speech are nouns, pronouns, adjectives, verbs, adverbs, prepositions, conjunctions, and interjections.
Most words in English can be classified as one of these eight parts of speech, although some, like determiners, are categorized separately in modern grammar.
The term part of speech refers to a word’s role in a sentence.
Some words can be different parts of speech depending on how they’re used in a sentence, such as work (noun and verb) and well (adverb, adjective, and noun).
The parts of speech fall into two word classes: open (parts of speech that regularly acquire new words) and closed (parts of speech that don’t readily acquire new words).