At least a quarter of a million words exist in the English language, and each one of them can be classified as one of the parts of speech. Among these words, there are both content words and function words; content words are words that have meaning, while function words are words used to connect other parts of speech to one another. When trying to classify a word as a part of speech, you must first determine whether that word is a content word or a function word.

Content Word or Function Word?

To determine whether a word is a content word or a function word, write it down in a sentence or find it used in a sentence and examine it. If the word provides meaning to the sentence, can be changed by adding a prefix or suffix or is identified by an signal word (article) such as "a," "and" or "the," it is most likely a content word. If, on the other hand, the word simply serves to provide structure to other words in the sentence, to connect words or is a signal word, it is probably a function word.

Classifying Content Words

If the word is a content word, then it must be a noun, verb, adjective or adverb. Nouns name a person, place, thing or idea. Words such as "dog," "Ohio" and "happiness" are all nouns. "Ohio," or any noun that names a specific place, is considered a "proper" noun. Verbs express action or a state of being; words such as "run," "jumped," "sat" and "seemed" are all verbs. Adjectives describe nouns, and include words like "pretty," "dark" and "yellow." Adverbs describe verbs, and usually answer questions such as how, when, where, and why.

Classifying Function Words

If the word to be classified is a function word, then it is a pronoun, preposition, conjunction, determiner or interrogative. Pronouns are words that substitute or represent nouns; "you," "she" and "I" are all pronouns. Prepositions mark the beginning of a prepositional phrase, which is a group of words containing a noun and its object. "After one hour" is a prepositional phrase in which "after" is the preposition, and "hour" is the object. Conjunctions, such as "and," "but" and "so" are words that join sentences, phrases or clauses. Determiners, or signal words, signal to the reader that a noun is about to follow. Words such as "some" or "the" are determiners. Interrogatives introduce questions and include words like "what," "how" and "why."

Additional Help

When a particular sentence is confusing, or it is too difficult to classify a particular word, remember that the dictionary explains the parts of speech for words. Consult a dictionary when stuck, then look at the sentence again to try and classify the word.