Sometimes writers are not sure about where to put commas in a list of adjectives.
Compare:
They visited a beautiful, elaborate mansion.
They visited a beautiful Victorian mansion.
The adjectives in the first sentence are separated by a comma because they are coordinate adjectives. They’re “coordinate” because they are equal in the way they describe the noun mansion.
The adjectives in the second sentence are not separated by a comma because they are not equal. They are “cumulative adjectives.” The adjective Victorian forms a unit with the noun mansion. The word beautiful describes “Victorian mansion.”
One way to determine whether a comma is needed is to replace it with the word and; if the sentence still makes sense, the comma is needed:
They visited a beautiful and elaborate mansion. (comma needed)
They visited a beautiful and Victorian mansion. (doesn’t make sense; no comma needed)
Another test is to reverse the order of the adjectives. If the sentence still makes sense when the adjectives are reversed, they are coordinate:
They visited an elaborate, beautiful mansion. (makes sense)
They visited a Victorian beautiful mansion. (does not make sense)
Here are some more examples for comparison:
She likes to read suspenseful mystery novels.
The queen wore a long silk gown.
The explorers suffered under a blazing, relentless desert sun
He grew up in a red brick house.
The school is noted for producing happy, relaxed, and well-behaved children.
When an adjective is repeated for effect, a comma separates the repeated word:
Many, many children are born to incompetent parents.
There is never a comma between the last adjective and the noun modified.
Nice and clear, good stuff.
Only it’s “red-brick house” not “red brick house” :).
One way to determine whether a comma is needed is to replace it with the word and; if the sentence still makes sense, the comma is needed:
Very nice tip! Thank you!
Oliver-long time no see.
Brick-red house – hyphen, brick tells what kind of red, and together brick-red describes the house
Red brick house – no hyphen if the brick house is red.
Red-brick house – hyphen if the house is made of red bricks.
Does it matter? Probably not. Both terms imply the same appearance: a house that is red and is made of bricks. Of course, I can imagine a house made of non-red bricks that is painted red. But, geeze, that’s starting to stretch a bit, even for me.
Regarding switching the order, not only does the reversed order need to make sense but also it needs to make the same sense. For example, a big American flag describes American flags and indicates the big one. However, the American big flag refers to a group of big flags and indicates the American one. The meaning changes when the order is reversed, so we know that the original, the big American flag, doesn’t need a comma. Here, big and American are not coordinate: they are cumulative, in which American describes flag, and big describes American flag.