Predominant vs. Predominate

Predominant and predominate are synonymous adjectives. Predominant is the older and much more common form. A number of handbooks and commentators hold predominate to be a mistake—a few insisting that the word is only a verb. But they are wrong. As an adjective predominate is somewhat more likely to turn up in technical writing than in general writing. The adverbs predominantly and predominately are a more even match in frequency than their base adjectives are, although predominantly is still significantly more common than predominately.