Generic nouns are nouns that refer to all members of a class or group. They are often used when making generalizations or talking about universal truths. Generic nouns can be singular or plural, and be used with or without articles.
Let’s take, for example, the very simple noun book. When writing a sentence, we might have a certain book in mind.
In this sentence, we’re clearly referring to a specific book, a fact that is particularly conspicuous because we have used the possessive pronoun my.
While there isn’t a specific book referred to in this sentence, it is clear that the speaker wants to acquire just one book (at least for now) and has nothing to say that applies to all books. Therefore book is not a generic noun here, but simply a common noun.
In this example, however, “a book” refers not to a single book, but to books in general. Therefore, book is a generic noun in this sentence.
It’s also possible to use a generic noun with the definite article, although this style is slightly old-fashioned.
You can even make general nouns plural, in which case no definite or indefinite article is needed. We call this the zero article.
This principle of zero article + plural generic noun can be applied to any generic class of things.
It is important to recognize whether a generic noun is used as a singular or plural, because it must agree with the verb that follows. Take the last sentence above, for example, and transform the plural generic noun computers into a singular generic noun.
Since the noun computer is now singular (taking the definite article the) the verb following it is now “has” rather than “have.”