Traditional grammar classifies words based on eight parts of speech: the verb, the noun, the pronoun, the adjective, the adverb, the preposition, the conjunction, and the interjection. Each part of speech explains not what the word is, but how the word is used. In fact, the same word can be a noun in one sentence and a verb or adjective in the next. The next few examples show how a word s part of speech can change from one sentence to the next, and following them is a series of sections on the individual parts of speech, followed by an exercise.
Books are made of ink, paper, and glue.
In this sentence, "books" is a noun, the subject of the sentence.
Deborah waits patiently while Bridget books the tickets.
Here "books" is a verb, and its subject is "Bridget."
We walk down the street.
In this sentence, "walk" is a verb, and its subject is the pronoun "we."