Pronouns are used to substitute noun phrases (NPs) to avoid repetitions and speed up the flow of information in speaking and writing. For example:
Are you looking for [that old torn hat]? It is lying there. (The pronoun 'it' refers to 'that old torn hat'.)
You know [that hammer that we lost]? It is lying right there. (The pronoun 'it' refers to 'that hammer that we lost'.)
Who is [the girl sitting in front of the fountain]? She is my cousin Susan.
The words that identify a pronoun’s referent is called an antecedent. In the examples above, 'that old torn hat', 'that hammer that we lost', and 'the girl sitting in front of the fountain' are the antecedents for the pronouns 'it', 'it', and 'she' respectively.
Can you imagine a day that you are not allowed to use pronouns?
Without pronouns, we'll have to repeat all the nouns. This makes speaking and writing repetitive and tedious.
Using a correct pronoun to refer to a person has unprecedented importance in today's society (e.g., they).
Using wrong pronouns can cause confusion, misunderstanding, or embarrassment in communication.