When a phrase or a clause of a sentence is used to denote an object, the whole phrase or clause becomes a noun.

For example

In the sentence:
To see the sun is pleasant.
the phrase To see the sun is used as a noun.
In the sentence:
That you have wronged me it doth appear.
the clause That you have wronged me is used as a noun.

Note

Nouns are also called substantives. A phrase or a clause used as a noun or a pronoun is called a substantive phrase or a substantive clause.

Proper and Common Nouns

Nouns are divided into two classes, proper and common.

A proper noun is the name of an individual object.

For example

The nouns James, Michigan, and France are proper nouns.

Most proper nouns are in the singular because they name a specific individual person or place. However, such plural names as Romans, Alps, and Azores are commonly considered proper nouns because a whole group is regarded as an individual.

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