An adjectives describes a noun. It tells you more about a thing a person.  
  An adjective tells us about the:  

a. colour: red, blue, yellow, green and many more.

For example:

i. I have a pencil (noun). 

ii. It is a red (adjective) pencil.


b. shape: round, square, oval and many more.

For example:

i. This is a table (noun).

ii. It is a round (adjective) table.


c. size: big, small, long, short and many more.

i. This is my house (noun).

ii. It is a big (adjective) house.


d. opinion: tasty, strong, crunchy and many more.

For example:

a. The sandwich is delicious.

b. Redang Island is a beautiful place.