There are three articles in English: a, an, and the. Articles used to be categorized as a separate part of speech, but in the recent grammar books, they are classified under the heading of adjectives, apparently, because they, like adjectives, come before nouns or refer to them.
When using nouns, you have to use an article before them, depending on the type of nouns: definite or indefinite, countable or uncountable, singular or plural, and whether they begin with a vowel sound or a consonant one.
a, an vs. the:
"a" and "an" are indefinite articles. They precede indefinate nouns.(Nouns that are not specific.)
"The" however is a definite article. It precedes definate nouns. (Nouns that are specific.)
Countable vs. Uncountable:
countable nouns can be:
1.Singular: We use "a/an" and "the"
2. Plural: We use "the"
Uncountable nouns have only one form:
We use only "the" if the uncountable noun is definite.
Using "a" and "an":
If the noun begins with a vowel SOUND, we use "an".
For instance, an apple, an orange, an animal, an athlete, an umbrella, etc.
Words like hour and honor begin with a silent "h" letter. So the first sound in these words is vowel. Thus, we use "an" before them.
On the contrary, if the noun begins with a consonant SOUND, we use "a". For example, a cat, a car, a hat, a man, etc.
Words like uniform and unicorn begin with a vowel letter and a consonant sound. Our focus is on sounds not letters. As long as they begin with a consonant sound, we use "a" before them.
Using "the":
We use "the" with singular, plural, and uncountable definite nouns.
1. It precedes nouns that are mentioned for the second time.
E.g: A cat showed up holding its kitten. The kitten was black.
2. It is used before nouns of which there is only one.
E.g: the moon, the sun, the universe, etc.
3. Before nouns that are known to both the speaker and listener.
E.g: Close the window, please.
4.Before nouns preceded by superlative adjectives.
E.g: the best player, the greatest dramatist, etc.
5. Before nouns preceded by ordinal numbers.
E.g: the first winner, the twentieth century, etc.
6. Before proper nouns.
E.g: the Nile River, the Red Sea, etc.
7. Before abbreviations.
E.g: the USA, the UK, the UNICIF, etc.
8. Before adjectives that describe a whole class of people.
E.g: the poor, the educated, the aristocratic, etc.
Using no artical(∅):
Sometimes we use no article before the nouns. This case is called ∅( no article). We use this case when we make a generalization when the noun is plural or uncountable.
Examples:
1. Cows give milk.
2. Milk is useful for the bones.
These two sentences begin with nouns that are not preceded by no article because they are generalized. Notice that the first noun is plural and the second is uncountable.
To put it differently:
Nouns can be:
Countable:
1. Singular» a/an ( indefinite)
2. Plural» the ( definite)
∅ (generalization)
Uncountable
(Only one form)» the (definite)
∅ (generalization)
Note:
We use articles before nouns or adjectives that precede nouns.
For example:
1. A tall man. 2. An elegant lady.
3. The strong wrestler.
Notice that the articles in the previous examples come before the adjectives(tall, elegant, strong) but they refer to the nouns( man, lady,wrestler).
With a little practice, it will be a second nature and you will master using articles. And remember: share and invite your friends. ;-)