English words can always be classified, depending on the context in which they are used, as one of the following eight parts of speech.

1. Nouns name people, places, things, qualities, etc. Nouns are often, but not always, used with one of the three articles: a, an, or the. Nouns that begin with a capital letter are called proper nouns; nouns that begin with a lowercase letter are called common nouns.

2. Pronouns are substitutes for nouns. Without pronouns our language would be unnecessarily repetitive and boring. Some of the common pronouns are you, he, she, we, our, they, who, everybody, either, and that.

3. Verbs give commands or say what action nouns or pronouns are involved in. The action might be in the present, past or future.
Verbs may also tell the condition or state of nouns or pronouns. Common verbs in this group are parts of the verb to be: am, are, be, been, being, is, was, were.

Some verbs act as helper verbs. They help complete the action that a speaker or writer is describing. The usual helper verbs are the eight parts of the verb to be and the following: can, could, do, did, does, has, have, had, may, might, must, shall, should, will, would.

4. Adjectives describe nouns or pronouns and are some of the easiest words to classify. Some examples of adjectives are angry, pleasant, rich, poor, yellow, blue, fraudulent, dishonest, loyal, inexpensive. Sometimes a verb form ending in -ing can be used as an adjective as in a domineering spouse. Also, the three articles can be called adjectives.

5. Adverbs change or clarify the meaning of a verb, an adjective or another adverb. Adverbs, which often end in -ly, usually answer the questions how, how much, when and where. Some adverbs are tomorrow, yesterday, surprisingly, regularly, often, very, seldom.

6. Prepositions show how words, nouns or pronouns relate (in position or time, etc.) to some other word in the sentence. The English language has many commonly used prepositions such as on, off, out, in, above, below, over, under, to, from, of, inside, outside, according to, notwithstanding, regardless of, apart from, up, down. Prepositions will be followed by the noun or pronoun they are related to as in to the north, from the supervisor, according to the agreement.

7. Conjunctions are connecting words or groups of words. These useful parts of speech come in three varieties:

A. Coordinating conjunctions join two words or groups of words that are grammatically the same. If you use the first letter of each of the conjunctions in this group to make the acronym FANBOYS, it should be quite easy to remember the complete list: for, and, nor, but, or, yet, so.
B. Correlative conjunctions work in pairs. Some examples of these common connective words are whether...or, either...or, not only...but also, both...and.
C. Subordinating conjunctions connect dependent clauses with independent clauses in a sentence. These conjunctions will be followed by a subject and its verb. Some subordinating conjunctions are since, when, where, once, because, if, after, although, though, even though, unless.

8. Interjections indicate strong or sudden emotion. Some interjections are ouch! darn! and the four-letter words used by some people.

9. Articles (a, an, the) are usually a problem only for someone who is learning English as a second or other language. Articles are used only with nouns but are difficult to master. There are many exceptions to the rules. However, anyone can eventually master using articles, but it often takes a long time.

Here are three helpful rules:

1. Use the when you refer to a specific noun. (The focus is on one particular person, place or item.)
     Example: The salespeople need a course in customer relations. (Only that group of employees needs training.)
2. Use a when you refer generally to a noun. (There is no need to focus on one person, place or item.)
     Example: We need a new computer desk. (Any suitable desk will make us happy.)
3. Use an the same as you use a but only before a noun beginning with a vowel sound.
     Example: An insect bit Raquel while she was sleeping. (She doesn’t know which kind it was.)