A demonstrative pronoun points out a noun.
- From this bench, you get a great view of the Eiffel Tower.
The demonstrative pronouns are: this, that, these, and those.
Distance and location are very important with demonstrative pronouns.
For subjects that are close, use this (singular) and these (plural).
For subjects that are at a distance, use that (singular) and those (plural).
Interrogative Pronouns
An interrogative pronoun introduces an interrogative sentence, or question.
- What is at the top of the Eiffel Tower?
The interrogative pronouns are: what, which, who, whom, and whose.
Relative Pronouns
A relative pronoun introduces a subordinate clause, or dependent clause. It relates the subordinate clause to the independent clause.
- Is this the bridge that I must take to get to the Eiffel Tower?.
The relative pronouns are: that, which, who, whom, whose.
*On a side note, when and where are relative adverbs, not relative pronouns.