Word choice: Predominate and predominant

These two sentences stopped me recently — one from a Twitter feed, the other from a piece I was copy-editing.

ACLU warns General Assembly to stop using predominately Christian prayers to start sessions.

Inspired by her travels to Mound Bayou, Miss., the nation’s largest predominately black town, Marshall-Linnemeier’s exhibit spins off images of experimental plantations set up during the Civil War by the Union government at Davis Bend and Port Royal.

The word in common is predominately. I changed it to predominantly in the story I edited. Here is why.

Predominate is best used as a verb. So we would write that “Robins predominate in early spring bird counts,” meaning that more robins are counted than any other species. Predominant is the best choice for an adjective. We would write that “The northern cardinal is the predominant species in early spring bird counts,” meaning that more cardinals appear in the bird count than members of any other species.

When we need an adverb, we choose predominantly.

You will get an argument on this from usage experts. They will say that predominate has been used as an adjective for years and years, but that it is merely less common than predominant in modern usage. Dictionaries list predominate as an adjective. But other experts, Bryan Garner prominent among them, follow the reasoning I laid out above. So the predominate/predominant distinction is one that is often taught in copy editor training.

In the end, this is one of those choices copy editors make sometimes to keep prescriptivists off our backs. We know that experts would be on our side if we let predominately slip by, but we also know that there is no harm and some benefit in changing it and we have experts on that side, too. I must say that I like to keep the distinction; it just makes sense to me.

Oddly, there is little debate over dominate (verb) and dominant (adjective). Dictionaries do not list dominate as an adjective. You will be on solid ground if you change dominately to dominantly.

P.S. I also corrected what might be perceived as a misplaced modifier at the beginning of the sentence I edited.

Inspired by Mound Bayou, Miss., the nation’s largest predominantly black town, Marshall-Linnemeier’s exhibit spins off images of experimental plantations set up during the Civil War by the Union government at Davis Bend and Port Royal. Davis Bend is where Mound Bayou’s founders were enslaved.