When preceded by the
, a singular countable noun can be used to represent something as a class.
telephone is a modern convenience. The
horse is a domesticated animal. The
eagle is a bird of prey.
In the first example, the telephone
refers to telephones considered as a class. Likewise, in the other examples, the horse
refers to horses considered as a class, and the eagle
refers to eagles considered as a class. A
is referred to as the indefinite
article because it can be used to refer to something in general terms. A
are often used in general statements.
bank account can provide a
good means of saving money. An
accountant must have a
good knowledge of arithmetic. A
good pair of scissors should be used for cutting cloth. Source