The Indefinite Article
Origin of the indefinite article:
The indefinite article a, an, comes from the old Anglo-Saxon numeral an (one). This later weakened into a, hence the two current forms a and an, which became the indefinite article in modern English. One, the modern form of the numeral, also derives from the ancient form an through a change in pronunciation.
Pronunciation:
The indefinite article, generally unstressed, is pronounced like “uh” in a muffled manner. The form a is pronounced as written, while the form an is pronounced as written and is linked to the following word.
Gender and number:
The article a, an serves all three genders and does not have a plural form. Example: a boy; a girl; a book; an animal — boys; girls; books; animals.
”Use of the indefinite article ”a:
The form a is used:
a) Before a consonant: a man; a child; a fine animal; a pleasant idea.
b) Before an aspirated h: a hero; a harvest; a horrible sight.
c) Before w and y: a window; a yard; a woeful sight; a yearly event.
d) Before the sound “ju” as in “uniform,” regardless of its spelling, and before “one.” Example: a uniform; a university; a ewe; a European conflict; a one-eyed man.
Use of an.
The form an is used:
a) Before a vowel: an animal; an idea; an unpleasant man; an ideal king.
b) Before a silent h: an heir; an honour; an honest person; an hour, and their derivatives.
General rule of use:
The indefinite article is generally used only before a singular countable noun. However, it can transform an uncountable noun, with a general sense, into a countable noun with a restricted sense.
Example: Great courage is required to be an explorer.
He required a peculiar (sort of) courage to explore that country.
Speech is silver, but silence is golden.
A (period of) silence fell over the company when the orator came in.
Special rules of use.
a) The indefinite article is used before a predicative or appositive noun unless the title is suitable for only one person in the given time and place.
Example: My father is a doctor. Nelson, a famous admiral.
but: He was mayor two years ago. Mr. Roosevelt, president of the U.S.A.
If the appositive noun refers to a unique thing or person, it is preceded by “the.”
Example: London, the capital of Great Britain, is built on the Thames.
b) After a preposition followed by a singular countable noun or one that has become countable.
Example: I went out without an umbrella. (Countable noun.)
He fought with great courage. (Uncountable noun.)
He fought with a (sort of) courage worthy of better success. (Countable noun.)
Also compare: an idiot of a kettle: a brute of a man: a devil of a boy, etc. After “of” introducing an adjective, the article is omitted.
Example: Such a king does not deserve the name of king.
c) After “as” (§ 289, c) and “what” and “such” before a singular countable noun (298, a).
d) Before nouns expressing the characteristic traits of a physical or moral portrait, where French would use the definite article.
Example: He had a rough voice, but a kind heart.
Il avait la voix rude, mais le cœur tendre.
e) After a number expressing the value of a unit. (§ 102).
Placement of the indefinite article “a” ,”an.”
a) “A,” “an” are placed before a noun used alone or before the attributive adjective.
Example: He is in a hurry.
She is a pretty girl.
I saw a very nice hat in this shop.
b) With “so,” “as,” “too,” “how,” the indefinite article “a” or “an” is placed between the adjective and the noun. For example, “He was in too select a circle“ or “She is as pretty a girl as her sister.”