2. The indefinite article a (or an) designates an object as merely one of a general class or kind.

The article a is a fragment of ān (pronounced ahn), the ancient form of the numeral one; an keeps the n, which a has lost. The is an old demonstrative, related to that.

174. The with a singular noun sometimes indicates a class or kind of objects.

Note. In this use the is often called the generic article (from the Latin genus, “kind” or “sort”). The singular number with the generic the is practically equivalent to the plural without an article. Thus in the first example the sense would be the same if we had, “Scholars are not necessarily dryasdusts.”

175. An adjective preceded by the may be used as a plural noun.

176. An is used before words beginning with a vowel or silent h; a before other words. Thus,—