Adjective order concerns the order in which adjectives are used in a phrase. They usually follow this order:
age color origin material purpose
a new red Swiss plastic army knife
We can have other types of adjectives which we put before the age. These are general adjectives about the size, the shape and our opinion of the noun. Often we can change the order of these adjectives but we usually put the most important first.
Here we are concerned with taste:
a tasty big sandwich
But if we think the most important thing about the sandwich is its size, we can say:
a big tasty sandwich
Having said all this, the order of adjectives can be changed for different literary effect and is not set in stone.
When you write, it is best not to use too many adjectives. Certainly, never more than two or, at most, three in a phrase:
The sharp, Swiss army knife pierced my skin.
I scoffed down a big, thick sandwich.
Otherwise it can start to look clumsy:
The old, sharp, red, Swiss army knife pierced my skin.
I scoffed down a two-dollar, tasteless, big, thick, crusty, homemade sandwich.
Mnemonic – OSASCOMP
The mnemonic OSASCOMP* can be used to help remember the order in which adjectives should appear:
Opinion, Size, Age, Shape, Color, Origin, Material, Purpose.
* this isn’t easy to remember; however try this:
On Saturday And Sunday Cold Ovens Make Pastry
As a side note, did you know that IWEeb TEFL invented this mnemonic which is now used extensively amongst English teachers and students?