THE BASIC TYPE OF ADJECTIVES
An opinion adjective explains what you think about something (other people may not agree with you). Examples: silly, beautiful, horrible, difficult
A size adjective, of course, tells you how big or small something is. Examples: large, tiny, enormous, little
A shape adjective describes the shape of something. Examples: square, round, flat, rectangular
An age adjective tells you how young or old something or someone is. Examples: ancient, new, young, old
A color adjective, of course, describes the colour of something. Examples: blue, pink, reddish, grey
An origin adjective describes where something comes from. Examples: French, lunar, American, eastern, Greek.
A material adjective describes what something is made from. Examples: wooden, metal, cotton, paper
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").
KEEP THIS CHART IN YOUR MIND...
Practise a bit with an online EXERCISE here. (click)
And remember, apart from these posts on Grammar Tips, you can always check the GRAMMAR PAGE (up above section, underneath the heading of the Blog).