Demonstrative pronouns are easy to remember because they are often accompanied by a demonstration: when we speak, we use our hands to show them. For the demonstrative pronouns this, that, these, and those, we point with our finger or gesture with our hands in the general direction of the thing we’re talking about. For the demonstrative pronouns none and neither, we often make a gesture implying rejection or emptiness.
This: singular and close to the speaker
I’ll have this little chocolate cake.
That: singular and relatively far away from the speaker
I’ll also have that strawberry cake, the one on the bottom shelf.
These: plural and close to the speaker
I’ll have three of these walnut biscuits.
Those: plural and relatively far away from the speaker
Are those butter tarts? I’ll have four of those, please.
How many sugar-free, all-natural cookies? None, thanks.