A pronoun is a word that substitutes for a noun or a noun phrase. Pronouns are classified into 6 types: personal pronouns; demonstrative pronouns; indefinite pronouns; relative pronouns; interrogative pronouns; and reflexive and intensive pronouns.

Demonstrative pronouns identify people or things by directing attention to them.

Note: The demonstrative pronouns are identical to the demonstrative adjectives. The part of speech of each word is determined by its function in the sentence.

• This book is my favorite. [In this sentence, "this" is a demonstrative determiner that modifies the noun "book."]
• This is my favorite book. [In this sentence, "this" is a demonstrative pronoun functioning as the subject.]