exceptional uses of articles

Answer 1

1) We use the for a particular reason. It is used for a definite purpose.

2)We use a in front of consonants. It is used to denote singular nouns. SUppose. " a student , a bright child.. " etc

3) AN - We use it in front of vowels. a e i o u . however, sometimes, even in front of words beggining with vowels. Suppose, we don't say an uniform , an unicorn ,

Answer 2

http://grammar.ccc.commnet.edu/grammar/determiners/determiners.htm#articles