#demonstrative determiners

sing.         pl.

this          these

that         those

This,That - change singular countable and uncountable nouns.

These,Those - change plural countable nouns.

this/these - head nouns as being closer to speaker.Head noun closer in time(more recent).

that/those - head nouns as being farther away and further away in time.

this/these + head noun - introduce new information and precede nouns of high relevance to the speaker.

Demonstrative determiners are used to point out things or people. They must agree in number and gender with the noun the introduce.

this: este (masc, sg), esta (fem, sg)

that: ese (masc, sg), esa (fem, sg)

that (over there): aquel (masc, sg), aquella (fem, sg)

these: estos (masc, pl), estas (fem, pl)

those: esos (masc, pl), esas (fem, pl)