The Demonstrative Adjectives basically demonstrate where the noun is or in other words the location of the noun.  The noun could be close “this” – “esto”, slightly further away “that” –  “eso” or even further away “that one over there”  –  “aquel”.

There are several forms of each one.   Masculine and feminine, singular and plural.  There is also an option when we don’t know what the noun is and therefore can’t tell if the word is masculine or feminine.

You will notice that the mascule singular does not follow the expected pattern.