Hyphen With Compound Modifiers

A compound modifier is two words connected by a hyphen, which acts like one adjective. Usually, these words can be used as individual modifiers, so the hyphen is required to clarify the meaning; for instance, American can be a noun or an adjective. When there are several of these words together, hyphens can make it clear as to which word is playing which role.

It’s recommended you not take down any load bearing walls when renovating.

In this sentence, it sounds like you shouldn’t take down any load which is holding up a wall. A hyphen should be inserted between load and bearing, so we understand not to take down any walls which are holding up a load.

It’s recommended you not take down any load-bearing walls when renovating.

He’s training to become a hair-stylist.

What color of eye-shadow goes with this outfit?

This rock-hard cake is absolutely impossible to eat.