Those Things And Them Things

[arjay]

We all know that it is a grammatical error to say them things,but how can it be explained to a foreign student learning learning English,please?

[grasscarp]

Give examples
I don't like those things you have in the hallway.
You think they should be there - I really don't like them.
So those with plural nouns. Them to replace a plural noun.
Them things, them cups etc never - has to be these or those.

[arjay]

Thank you grasscarp for our prompt and helpful answer