A Word, Please: 'Comprise' is uncompromising

A lot of people like to use the phrase "is comprised of" -— about 136 million of them, if a recent Google search is any indication.

"Houston is comprised of many neighborhoods," one website tells me. "Workforce planning is comprised of a number of key tasks," another insists. And, my favorite, "Erythrocyte spectrin is comprised of many homologous triple helical segments." (Like we didn't know that already.)

Skimming through all these uses of "comprised of" supports my longtime suspicion that people use this phrase when they're trying to sound official, formal or informed. There's nothing wrong with striking a formal tone in contexts that call for it. In academic writing and some business writing, formal language is requisite. (It's also handy when arguing politics with hardheaded, uninformed relatives. But it's too early to start planning for the holidays just yet.)

In many cases, the people using "comprised of" are choosing it over the much simpler "has." Perhaps they feel that "Erythrocyte spectrin has many homologous triple helical segments" just doesn't have the same cachet. So they choose "comprised of" because they think it will make readers to take them seriously. And that's why it's so it ironic.

According to leading style sources, "comprised of" is wrong.

To comprise, they say, means to contain or to be made up of: Houston comprises many neighborhoods. Houston contains many neighborhoods. They mean the same thing.

Notice there's no need for "of." The "of" usually emerges from a common confusion about "compose" and "comprise." Sentences like "Houston is composed of many neighborhoods" are common and correct. And it's easy to see how this structure seeps into the minds of people who want to fancy up their prose with "comprise." But they're the very people who should be careful never to pair "comprised" with "of."

But before we start analyzing that "of," let's start with the basics. Here, according to the style guides, is the easiest way to understand the difference between compose and comprise: The whole comprises the parts, and the parts compose the whole. The city comprises neighborhoods, and neighborhoods compose the city. Spectrin comprises segments, and segments compose erythrocyte.

In fact, you could argue that compose and comprise are basically opposites. "Comprise" meaning "to be made up of" and "compose" meaning "to make up."