'A', 'an' and 'the' are called 'articles'. They go before nouns and tell us about those nouns: 'a shirt' refers to any shirt; 'the shirt' refers to one specific shirt.
Indefinite Articles: A, An
'Indefinite' means that something is not defined or specified.
The indefinite articles 'a' and 'an' refer to non-specific things. 'A' becomes 'an' when the word that follows starts with a vowel.
- I am a doctor. (= 'an doctor' is incorrect)
- I am an actor. (= 'a actor' is incorrect)
We use 'a' or 'an' to refer to one non-specific person/place/thing:
- Please choose a card. (= choose one card. Any card is fine)
The word 'definite' comes from the word 'define' (to clearly say what something is).
The definite article, 'the', makes the noun that comes after it more specific. We use 'the' to refer to:
1. Things that have already been mentioned:
- "I see a dog. The dog is cute."
- (= The dog in the first sentence is cute.)
2. Things that don't need to be specified:
- "Can you close the door?"
- (= There is only one door in the room: 'the' door.)
- "the world / the sun / the sky / the universe"
- (= There is only one world, one sun, one sky, one universe.)
When there is an adjective, 'a(n)' and 'the' go before the adjective. For example, "Starbucks is a famous coffee shop" or "I want the blue shirt."
