Use "this" when something is nearby.
Use "that" when something is a distance away. something is a distance away.
- This book belongs to you.
- That dog is asleep.
- This shirt is mine.
- That car is his.
"These" and "those" are the plural forms of "this" and "that".
- These children have been reading all afternoon. (Meaning the ones in the same room)
- These are mine.
- Those children have been playing outside all day.
- Those are yours.
- Think "Those" has an "O" as a dominate sound. That "o" stands for "over there" Use "those" for things "over there"