The parts of speech are a system for classifying words in the English language. We group
words in categories that share common characteristics in order to talk about the language more
easily. All English words fall into these eight parts of speech: verbs, nouns, pronouns, adjectives,
adverbs, prepositions, conjunctions, and interjections. Many English words can function as
more than one part of speech. For example, when you book a plane flight, it is a verb; when you
read a good book, it is a noun; and when you have book knowledge, it is an adjective. Thus, the
function of a word in a sentence, rather than the word itself, always determines its part of speech in
that sentence. Knowing the eight parts of speech is important because it will allow you to better
identify how words are functioning in a sentence. Punctuating a sentence correctly often depends
on the writer’s ability to correctly identify the function of a given word.