this + is + complementUse this for one thing near you. With be, use is.
Use this, that, these, and those as pronouns when no noun follows. Choose by distance and by one thing or more than one.
this + is + complementUse this for one thing near you. With be, use is.
that + is + complementUse that for one thing farther away in space, time, or attention. With be, use is.
these + are + complementUse these for two or more things near you. With be, use are.
those + are + complementUse those for two or more things farther away. With be, use are.
What + is + this/that + ?Ask about one thing with What is this? or What is that?
What + are + these/those + ?Ask about more than one thing with What are these? or What are those?
This is mine.
Use this for one thing near you.
Use them when you point to something near or far: This is nice. Those are too expensive.
Use them when you choose between options: I'll take this, not that. These are better than those.
Use them to identify what you mean after the context is clear: Who left this? Those are Maria's.
Not when they are pronouns. They can stand alone if the thing is already clear: This is better. Those are mine.
They can also show distance in time or attention: That was a good idea. These are the points we need now.
USE_WITHOUT_NOUNw5Use demonstrative pronouns when the thing or things are already clear from the situation. Do not add a second noun if this, that, these, or those already stand alone.
CHOOSE_NEAR_OR_FARw5Use this and these for things near the speaker. Use that and those for things farther away in space, time, or attention.
MATCH_ONE_OR_MOREw5Use this or that for one thing. Use these or those for two or more things.
BUILD_BE_SENTENCESw5When the demonstrative is the subject, match it with the correct form of be. Singular takes is; plural takes are.
ASK_WHAT_IS_THIS_THATw4Use singular questions for one thing and plural questions for more than one. Keep the same near/far choice when you point or refer back.
USE_FOR_CHOICESw3Use this, that, these, and those when you point to options, compare items, or identify what you mean. The noun can stay unstated because the context shows it.