USES OF "A"

USES of A••

1. In the sense of one 
~example. He could not speak a word to save himself.
With 'one' (since one begins with sound of w) 
~example. A one-man show, a 1 rupee note.
2. Before words beginning with consonant sound.
~example. a boy, a boxer,a dog.
3.With vowel letters having l
 having constant value. 
~example. a University, a unique article, a unit, a European language.
4. With units and rate.
~example. He earns rupees 500 a month.
Rice sells 10 rupees a kilo.
5. In exclamatory expressions before singular countable nouns.
~example. What a pretty girl!
how is sunny day!
6.When two subjects or articles are thought of as a single unit.
~example. He was ready with a cup and saucer.
A cigarette is made up of paper and tobacco. 
7.With certain expressions of quantity ~example. a lot of, a dozen, a great deal, a couple.
8.With a person's name to indicate that the person is perhaps unknown to the person addressed.
~example. A Mr. Raja is at the door. 
9.With a special meal (to celebrate something or in someone's honour) ~example. I called my friends to a lunch to celebrate my success.
 A dinner was arrange to welcome the principal.
10. To make a common noun or Proper noun.
~examples. This man is 'a second Newton' (this phrase means a philosopher as great as Newton)
'A Daniel' came to judgement.
(the phrase means a wise man)