Opinion

An opinion adjective explains what you think about something (other people may not agree with you).
Examples: silly, beautiful, horrible, difficult

Size

A size adjective, of course, tells you how big or small something is.
Examples: large, tiny, enormous, little

Age

An age adjective tells you how young or old something or someone is.
Examples: ancient, new, young, old

Shape

A shape adjective describes the shape of something.
Examples: square, round, flat, rectangular

Colour

A colour adjective, of course, describes the colour of something.
Examples: blue, pink, reddish, grey

Origin

An origin adjective describes where something comes from.
Examples: French, lunar, American, eastern, Greek

Material

A material adjective describes what something is made from.
Examples: wooden, metal, cotton, paper

Purpose

A purpose adjective describes what something is used for. These adjectives often end with “-ing”.
Examples: sleeping (as in “sleeping bag”), roasting (as in “roasting tin”)