3 common comma errors

1. “The giant, blue eyeball that washed up on a Florida beach likely came from a swordfish.”

The adjectives giant and blue are noncoordinate, which means they’re not parallel in function. You can say, of course, that an eyeball is giant and that it is blue, but the second test of adjectival coordination, whether the words can gracefully be transposed, does not work; “the blue giant eyeball” is awkward. Why?

A convention in English called the royal order of adjectives assigns specific starting positions to different types of descriptive words, and size precedes color. Therefore, “blue eyeball” becomes a temporary compound modified by giant, and therefore no intervening punctuation is required: “The giant blue eyeball that washed up on a Florida beach likely came from a swordfish.”

2. “Move over vampires, goblins, and haunted houses, this kind of Halloween terror aims to shake up even the toughest warriors.”