Commas, Part 7

Commas, Part 1
Commas, Part 2
Commas, Part 3
Commas, Part 4
Commas, Part 5
Commas, Part 6

You've doubtless heard of adjectives, eh? They're the words that modify (by which we most often mean describe) nouns. The word big in the phrase the big dog is an adjective. The word horny in the phrase the horny dog is also an adjective.

But what about the big horny dog? Should that be written with a comma between the two adjectives?

Yes. Yes, it should. But why?

Welcome to the world of stacked adjectives. They come in two main forms:

• coordinate adjectives
• cumulative adjectives

Think of it this way: let N be a noun, and let A1 and A2 be two coordinate adjectives. This is the situation we see with big, horny dog.

A1 = big
A2 = horny
N = dog

→ a (A1, A2) N = a (big, horny) dog

In a coordinate-adjective situation, the two adjectives have equal status, but more important: each adjective directly modifies the noun, hence the need for a comma to separate the equal-status adjectives. So to break this down logically: saying "big, horny dog" is like saying, "The dog is big, and the dog is horny." The independent clauses on either side of the and have equal weight, and just as you can separate two independent clauses with a comma-conjunction, you should separate your coordinate adjectives with a comma. In other words:

A1 modifies N, and
A2 also modifies N.

In a cumulative-adjective situation, as with the phrase horny police dog, the adjective farthest away from the noun modifies both the closer adjective and the noun. So when we speak of a "horny police dog," we are not saying "The dog is horny, and the dog is police." We are only saying that "the police dog is horny." So the cumulative-adjective logic looks like this:

A1 modifies both A2 and N, and
A2 only modifies N.

Or for you coder types, we could use "nested" logic:

A1(A2 + N) [i.e., "horny" modifies both "police" and "dog": it's a horny(police dog), not a (horny police)dog—a dog employed by horny policemen]

This may strike certain grammar scolds as a weird thing to say because we've all been taught that adjectives can't modify adjectives: only adverbs can modify adjectives (e.g., "Those're some awfully big titties, there, Jethro."). Well... consider this a not-so-rare exception to that sacred rule. It happens every time there are cumulative adjectives.

There may be times when it's unclear whether you're dealing with coordinate or cumulative adjectives. In such cases, it's fine to make a judgment call, but in many cases, it's not. I wrote a post on this topic back in 2015. In that post, I quoted Mignon Fogarty, a.k.a. the Grammar Girl, who offered the following interesting locution: exquisite custom houseboat. As my post title from 2015 asks: to comma, or not to comma? Is the adjective pair exquisite custom an example of coordinate or cumulative adjectives? Hint: is it proper to say the houseboat is exquisite and custom? If the answer is no (and it is no), then you're looking at cumulative adjectives, so there should be no comma. The basic rule, then, is:

Coordinate adjectives take a comma between them;
cumulative adjectives don't.

Simple enough, I hope?

QUIZ
In the comments section or on a different writing surface, rewrite the following sentences with commas if needed. Do not rewrite if there's nothing to correct. Highlight the space between the brackets to see the correct answers.

1. Barton entered the malodorous chow hall, hungry despite the reek of bull testicles.
2. Breasts flapping defiantly in the gale, Wonder Woman aimed her thunder-spear directly at Death Rhino's ponderous dangling scrotum.
3. Whining putrescent lovers of central planning can eat my nasty leprous crotch.
4. The nimble battle cruiser Penetrator slipped past the oblivious enemy fleet, launching behind it a clutch of deadly sexual-arousal torpedoes.
5. My bloated disgusting cat desperately needs to follow the keto diet.

ANSWERS
[1. Barton entered the malodorous chow hall, hungry despite the reek of bull testicles.
2. Breasts flapping defiantly in the gale, Wonder Woman aimed her thunder-spear directly at Death Rhino's ponderous, dangling scrotum.
3. Whining, putrescent lovers of central planning can eat my nasty, leprous crotch.
4. The nimble battle cruiser Penetrator slipped past the oblivious enemy fleet, launching behind it a clutch of deadly sexual-arousal torpedoes.
5. My bloated, disgusting cat desperately needs to follow the keto diet.]