The words a and an are called indefinite articles. We can use them with singular nouns to talk about any single person or thing.
Deciding which indefinite article to place in front of a word depends upon the initial sound of the word, not the first letter of the word.
‘A’ is used before words beginning with a consonant sound.
e.g.
| a usual | a student | a doctor | a hotel |
The article ‘an’ should be placed before words that begin with a vowel sound.
The initial sound should be a, e, i, o, or u.
| an hour | an elephant | an actor | an ice-cream |
1. ‘A’ must be used before words which begin with a vowel symbol pronounced with the same sound as the ‘y’ or a ‘w’-like sound.
e.g.
| a Europe | a uniform | a union | a unique |
| a unitarian | a united | a university | a usual |
| a useful thing | a year | a one-eyed giant | a one-dollar note |
2. Sometimes, ‘an’ is found before words beginning with the letter ‘h’.
Silent ‘h’: ‘an’ is used before these words:
e.g.
| an hour | an honour | an heir | an heirloom |
| an hourly | an honorarium | an honesty | an honorary |
But this practice is going out. If ‘h’ is pronounced, ‘a’ is used:
e.g.
| a hotel | a house | a horse | a human being |
3. We use AN before abbreviations that begin with a vowel sound.
e.g.
| an M.A., | an M.Sc., | an M.B.B.S., | an M.L.A. |
| an N.C.C Officer | an M.Com., | an M.C.A | an M.B.A., |
4. ‘a’ or ‘an’ must be used before a singular noun standing for things that can be counted.
e.g.
| England is a country | London is a city |
| Rice is a cereal | A dog is an animal |
5. ‘a’ or ‘an’ must be used before the names of professions.
e.g.
| His father is a doctor |
| She is an engineer |
6. Words like hero, genius, fool, thief and liar take the indefinite article.
e.g.
| Beware of that fellow; he is a liar |
| My friend is a genius |
7. The following word has indefinite article. Such + a/an + noun (or) Such + a/an + adjective + noun
e.g.
| Such a thing | Such a person |
| Such an honour | Such an interesting story |
8. The following word has indefinite article. so + adjective + a/an + noun
e.g.
| So interesting a person | So nice an opportunity |
9. ‘Few’ and ‘Little’ are negative meaning. ‘A few’ and ‘a little’ are positive and mean 'some'
e.g.
| He has little knowledge of this subject | I have a little money on me |
| He has few friends | I have a few books on this subject |
10. In its original numerical sense of one; as,
e.g.
| Not a word was said | Twelve inches make a foot |
| A bird in the hand is worth two in the bush | I have a book |
11. A, an = one thing or person.
e.g.
| Sara works in a bank | Can I ask a question? |
| I have not got a car | There’s a woman at the bus stop |
12. We use a/an when we say what a thing or a person is.
e.g.
| The sun is a star | Football is a game |
| A mouse is an animal. It’s a small animal | He is a very jolly person |
13. We use a/an for jobs, etc.
e.g.
| I am a dentist | He is a teacher |
| She is a student | Are you an engineer? |
e.g.
| A dog is a faithful animal | Dogs are faithful animals |
Non-defining relative clause
Non-defining relative clauses are placed after nouns which are definite already.
The adjective clause which does not define the noun before it but gives additional information about the noun is called the non-defining relative clause.