From Teflpedia

A demonstrative (/dəˈmɒnstrətɪv/) is a determiner, that is, a word used to refer and identify people and things. In English these are:

Type Singular Plural
Close this these
Distant that those

They can be used independently or dependently. When used dependently they have a noun phrase following them, e.g. "this chair", "these pens". These are dependent demonstratives, known in traditional grammar as demonstrative adjectives. However, when used independently they act as pronouns, known as demonstrative pronouns.

Note they show number concord. They also reference spatial deixis.

Students may struggle with the /ð/ sound.