- stressed, before a vowel
- unstressed, before a consonant
- Used, instead of a, to reference something specific, already known to exist.
- Compare "I read a book." and "I read the book."
- Used with a stress, to show that the word following is special.
- Are you the John Smith that I went school with?
- Used with an adjective that acts like a noun to mean all of the people concerned
- The poor are always with us.
- the is called the definite article