What is the difference between “this” and “that”?

“This” and “that” are both used as demonstrative adjectives and demonstrative pronouns. Both are used to refer to singular nouns (e.g., “this book,” “that restaurant”).

This is used to refer to something that is relatively close to the speaker, and that is used to refer to something that is relatively farther away (e.g., “Take this book, and put it on that shelf”). The choice of “this” or “that” is greatly influenced by the context of a sentence.