1. Overview:
The articles "a" and "an" are used with singular nouns to talk about something for the first time or to describe a general idea. "The" is used to refer to something specific that both the speaker and listener know about. The zero article means no article is used, often with plural or uncountable nouns.
2. Cases of Usage:
Case 1: Use "a" before words that start with a consonant sound.
Example: I saw a dog in the park.
Case 2: Use "an" before words that start with a vowel sound.
Example: She is an artist.
Case 3: Use "the" when talking about something specific.
Example: The dog in the park is friendly.
Case 4: Use the zero article when talking about plural nouns or uncountable nouns in general.
Example: Dogs are friendly. (plural)
Example: Water is essential for life. (uncountable)
3. Exceptions or Things to Pay Attention To:
Some words start with a vowel but sound like they start with a consonant. For example, "university" starts with a "y" sound, so we say "a university."
Example: She goes to a university in London.
Also, "the" can be used for unique things, like "the sun" or "the president."
4. Additional Notes:
Be careful not to use "a" or "an" with plural nouns. For example, we say "I have cats," not "I have a cats." Remember to think about the sound of the word, not just the first letter, to choose between "a" and "an."
