The English parts of speech are the eight traditional categories (types) of words in English: nouns, pronouns, verbs, adjectives, adverbs, prepositions, conjunctions, and interjections. They separate words into groups based on their use: to name, to describe, to show action, to connect, etc.
It's important to understand them because they show how words are used in sentences. To speak English well you need to know how to form sentences, and where to use each type of word. (See English Sentence Structure for examples of how to use the English parts of speech in sentences.)
Nouns, pronouns, and verbs are the most basic building blocks of sentences. Yo cannot express a complete thought without them!
Nouns are names of a person, place, thing, or concept. Examples: child, Mary Smith, parents, beach, mountains, London, Korea, table, chairs, money, time, distance, peace, ideas.
Pronouns (I, you, he, she, it, we, they, me, him, her, us, and them, etc.) can take the place of nouns in sentences.
Verbs express action (go, find, make, get, take, live, die, eat, think, etc.) or state of being (be, seem, appear, need.)
You will find that many English words can be used as more than one part of speech. For example, many words can be used as either a verb or a noun: act, call, need, play, show, work, and many more. To act is to do something; (or to take the part of someone else in a play or other performance, as an actor does), an act is something that is done (or one part of a play.)
An interesting example of the way a word may change from one part of speech to another is the word 'hand.' It is usually a noun-- the part of the body that can hold things. However, we also use it as a verb: 'to hand', when a hand gives something to someone else. A teacher 'hands out' papers or asks students to 'hand in' their homework. A bank robber shouts, "Hand over the money!"
Adjectives describe nouns or pronouns. They usually occur before the noun they describe, or are connected to it by a verb like ‘to be.’ (The quiet man... The man is quiet.) Examples of adjectives: quiet, noisy, early, late, good, bad, long, short, green, red, Chinese, American, difficult, easy.
Determiners. Some linguists consider determiners as a category separate from adjectives (though they modify nouns as adjectives do.) They include articles (a, an, the), demonstratives (this, that, these, those), numbers, quantifiers like some, many, each, fewer, or none, and possessives (see possessive adjective list in the English Pronouns link above ).
Adverbs modify verbs, adjectives, or other adverbs. They show how, when, where, or how often something is done. Examples: well, badly, quickly, carefully, very, always, usually, often, rarely, never, now, soon, today, tomorrow, yesterday. Many adverbs are formed by adding -ly to adjectives and describe how an action is done. These follow the verbs they modify: he walked quickly; she spoke softly; they read carefully. Adverbs of frequency describe how often something happens, and usually come before the verb: He usually goes to the store on Tuesdays; Mary never drinks beer; They often help their neighbors.
Prepositions show relationships between parts of speech. (The pen is on the table. This book is for you. Airplanes fly over mountains. We’ll go with them. The meeting is at 7 o’clock tonight.)
Some common prepositions of location are: in, at, on, next to, beside, above, beneath, below, in front of, in back of, behind, near, close to.
Common prepositions of direction or movement are: to, from, away from, towards, over, under, around, through.
Some common prepositions of time are: in, at, on, before, after, during.
Other prepositions include with, for, of, because of, and instead of.
Conjunctions show the connection between parts of a sentence. Coordinating conjunctions like ‘and,’ ‘but,’ ‘so,’ and ‘or’ connect independent clauses in compound sentences.
Some conjunctions have two parts: either- or, neither- nor, both- and, not only- but also. Examples: We can either go to the store or to the party. Jim not only gave us directions, but he also led us through the first two intersections.
Subordinating conjunctions begin a dependent clause and show its relationship to the main (independent) clause in a complex sentence.
For examples of different types of subordinate conjunctions and how to use coordinating and subordinate conjunctions in sentences, see Compound Sentences, Complex Sentences, and Adverb Clause and Complex Sentence Practice.
Interjections are exclamations of feeling: Wow!, Oh, my! Hey! Many of them are not polite language: curses, “dirty” words, etc. (Be careful when you use these, even if you have heard them a lot. Some people find them very offensive, and they are inappropriate in most formal contexts.)
Go to Word Families to see examples of the different major parts of speech (nous, verbs, adjectives and adverbs) with demonstrations of their use. The List of Suffixes explains how word endings show the part of speech (or change one into another.)