It is
well known that the grammar of one's mother tongue is
something rather bizarre. All use them all the time
and nobody actually understands the way it works. In
computer programming the things are a bit different
- you have to know the programming language before you
can use it. With grammar it's the other way around.
You understand it when you know the language - when
it's actually already too late, because you know the
language. Now back to the demonstrative pronouns
- a thing that everybody uses for instance in the bakery's
pointing at something and saying I
want
that one.
The English language actually knows
four demonstrative pronouns, two in singular and two
in plural.
English
demonstrative pronouns
demonstrative
pronouns in singular
demonstrative
pronouns in plural
this
that
these
those
The demonstrative pronouns this
and these indicate something close in time and also
locally. They are used when a noun is put right after
them. That and those indicate something that is a bit
further in time and also locally. They also refer to
something that was just talked about. The
English demonstrative pronouns are used adjectival
(before a noun) and pronominal (instead of a noun).
A: This
coat is really lovely.
B: Oh, I'd rather like those
behind the mirror.
A: How can you say that?
They are real fur!
B: But these
fur coats are soooo in fashion!
In Spanish there are three
demonstrative pronouns (three for each gender and for
each number as you'll see). And then there is the differentiation
between the adjectival demonstrative pronouns and the
pronominal.