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."
So it's simple stuff until we start pondering that "of." The structure in "Houston is composed of neighborhoods" is passive, just as "The building was demolished" is passive. Passive structures make an object of an action into a grammatical subject of a sentence. The house isn't doing the demolishing. It's the thing being demolished. In the former example, Houston isn't doing the composing. It's the thing being composed -— being made up. That's the basic idea of passive voice.
The passive structure is common with "compose." The audience is composed of doctors and nurses. The state is composed of counties. In cases like these, it's probably more common than the active voice alternatives. Doctors and nurses compose the audience. The counties compose the state. Those sound less natural than their passive counterparts.
Comprise doesn't work so well in the passive form. The active "Stew comprises many ingredients" just loses something when converted to "many ingredients are comprised by stew." That's like saying "Ingredients are contained by stew," which is just weird. So "comprise" is almost never passive. And that's why, if you want to be proper, you should never pair "comprised" with "of."
Of course, if you're not as concerned with sounding fancy, you can follow the advice of the dictionaries and usage experts that say "is comprised of" is acceptable or, at the very least, idiomatic. But you erythrocyte spectrin bloggers should probably disregard that.
JUNE CASAGRANDE is author of "It Was the Best of Sentences, It Was the Worst of Sentences." She can be reached at JuneTCN@aol.com.