Day 173: Age, color, material, shape, and nationality adjectives are never coordinate.

You already know the rule about placing a comma between coordinate adjectives, discussed in Day 167. For example, you now know to place a comma between “musty” and “dilapidated” here:

“The musty, dilapidated hotel room was my new home.”

You can reverse their order, and you can add and between them without changing the meaning. This tells you that they are being used as coordinate adjectives.

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Some types of adjectives cannot be coordinate adjectives, regardless of whether they are first or second in the pair of adjectives. The meaning of the sentence will change if you reverse their order or if you add and between the two adjectives. As such, you will not need the comma. They are as follows.

 
  • Age: “The young tired man sat heavily on the trail.”
  • Color: “The inflated red balloon drifted away.”
  • Material: “A dirty cotton shirt hung over the fence.”
  • Shape: “He built a sturdy round house on his property.”
  • Nationality: “The attractive Spanish girl winked at me.”