Some examples of demonstrative pronouns would be the following:
Have you read this? (notice “this” is an pronoun because it takes the place of the noun “book” from the sentence above)
Please hand me that. (notice “that” is an pronoun because it takes the place of the noun “pencil” from the sentence above)
Did you intend to purchase these? (notice “these” is an pronoun because it takes the place of the noun “packs” from the sentence above)
He wanted to bring those to the party, but he didn’t. (notice “those” is an pronoun because it takes the place of the noun “gifts” from the sentence above)