Demonstrative adjectives point out which person or thing is meant. Examples are: that, this, these, those and such.

• Those mangoes were sweet.
• I don’t like that girl.
• That boy is very clever.
• I admire such things.

Demonstrative adjectives answer the question: which?

Notes:
This and that are used with singular nouns. These and those are used with plural nouns.

• This mango is sweet.
• These mangoes are sweet.
• That mango is sour.
• Those mangoes are sour.

Related posts:

1. Adjectives of Number (Numeral Adjectives)
2. Kinds of Adjectives
3. Adjectives
4. Parts of Speech I