The 9 Parts of Speech: Definitions and Examples

Parts of Speech
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A part of speech is a term used in traditional grammar for one of the nine main categories into which words are classified according to their functions in sentences, such as nouns or verbs. Also known as word classes, these are the building blocks of grammar.

Key Takeaways: Parts of Speech

  • Word types divide into nine parts of speech, such as nouns, prepositions, adjectives, and adverbs.
  • Some words can be more than one part of speech, depending on context and usage.
  • Interjections can be sentences on their own.

Every sentence you write or say in English includes a few words that fall into the nine parts of speech. These include nouns, pronouns, verbs, adjectives, adverbs, prepositions, conjunctions, articles/determiners, and interjections. (Some sources include only eight parts of speech but leave off interjections as a category.)

Learning the names of the parts of speech probably won't make you witty, healthy, wealthy, or wise. In fact, learning just the names of the parts of speech won't even make you a better writer. However, you will gain a basic understanding of sentence structure and the English language.

Word Classes

The parts of speech are commonly divided into open classes (nouns, verbs, adjectives, and adverbs) and closed classes (pronouns, prepositions, conjunctions, articles/determiners, and interjections). Although we can add to the open classes of words as language develops, those in the closed classes are pretty much set in stone. (See examples below.)

Some traditional grammars have treated articles as a distinct part of speech. Modern grammars more often include articles in the category of determiners, which identify or quantify a noun. Even though they modify nouns like adjectives, they are different in that articles are an essential part of the proper syntax of a sentence, and determiners are necessary to convey the meaning of the sentence. Adjectives are optional parts of a sentence.

In contemporary linguistics, the label part of speech has generally been discarded in favor of the term word class or syntactic category.

Noun

Nouns are a person, place, or thing (or even an abstraction, such as an idea). They can take on myriad roles in a sentence, from the subject of it all to the object of an action or any other (literal) thing in between. They are capitalized when they're an official name of something or someone. For example pirate, Caribbean, ship, freedom, Captain Jack Sparrow

Pronoun

Pronouns stand in for nouns in a sentence. Examples:​ I, you, he, she, it, ours, them, who, which, anybody, ourselves

Verb

Verbs are what happens in a sentence. They're either action words or show the state of being (is, was) of the subject of the sentence.  They change form based on tense (present, past) and the subject of the sentence (singular or plural). Examples:  sing, dance, believe, seem, finish, eat, drink, be, become

Adjective

Adjectives describe nouns or pronouns. They specify which one, how much, or what kind. Examples: hot, lazy, funny, unique, bright, beautiful, poor, smooth

Adverb

Adverbs describe verbs, adjectives, or even other adverbs. They specify when something happened, where, how, why, and how much. Examples: softly, lazily, often, only, hopefully, softly, sometimes

Preposition

Prepositions show a relationship between a noun (or a pronoun) and the other words in a sentence. They come at the start of a prepositional phrase. For example: up, over, against, by, for, into, close to, out of, apart from

Conjunction

Conjunctions join words, phrases, and clauses in a sentence. Examples: and, but, or, so, yet, with

Articles and Determiners

Articles and determiners function like adjectives by modifying nouns, but they are different than adjectives, in that they are necessary for a sentence to have proper syntax. Examples: articles: a, an, the; determiners: these, that, those; enough, much, few; which, what

Interjection

Interjections are expressions that can stand on their own as complete sentences. They are words that often carry emotion. Examples: ah, whoops, ouch, yabba dabba do!

How to Determine the Part of Speech

Only interjections (Hooray!) have a habit of standing alone, though they can also appear alongside complete sentences. The other parts of speech come in many varieties and may appear just about anywhere in a sentence.

To know for sure what part of speech a word is, look not only at the word itself but also at its meaning, position, and use in a sentence.

For example, in the first example here, work functions as a noun; in the second sentence, a verb; and in the third sentence, an adjective:

  • Bosco showed up for work two hours late.
    (The noun work is the thing Bosco shows up for.)
  • He will have to work until midnight.
    (The verb work is the action he must perform.)
  • His work permit expires next month.
    (The attributive noun [or converted adjective] work modifies the noun permit.)

Don't let this variety of meanings and uses discourage or confuse you. Learning the names of the basic parts of speech is just one way to understand how sentences are constructed.

Dissecting Basic Sentences

To form a complete sentence, you really only need two things: a noun (or pronoun standing in for a noun) and a verb. The noun gives us the subject, and the verb tells us the action the subject is taking, the predicate. 

  • Birds fly.

In this short sentence, birds is the noun and fly is the verb. The sentence makes sense and gets the point across.

  • Go!

You can have a sentence with just one word as well, but it doesn't break the above rule. This short sentence is still complete because it's a command to "you"; the pronoun, standing in for a noun, is just understood to be there. It is the subject. The sentence is really saying "(You) go!"

It's important to note that no other two-word class combinations can form a complete sentence unless it involves an interjection. You always need a verb to have a sentence. You cannot, for instance, use a pronoun and an adverb alone and have a complete sentence: She softly. This is not a sentence because we don't know what she's doing softly.

Next, we can add more information to our first sentence by including the other parts of speech.

  • Birds fly when migrating before winter.

Birds and fly remain the noun and verb. When is an adverb because it modifies the verb fly. 

The word before is a little tricky because it can be either a conjunction, preposition, or adverb depending on the context. In this case, it's a preposition because a noun follows it. The preposition begins an adverbial phrase (before winter) that answers the question of time when the birds migrate. It is not a conjunction because it does not connect two clauses.