Predominant and predominate express a similar idea: being the most common, noticeable, or influential. The main difference is how they work in a sentence.
Predominant is an adjective. Use it to describe a noun. It can come before that noun or follow a verb such as be.
- Cost was the predominant concern during the meeting.
- Bright colours are predominant in her paintings.
In the first sentence, the word describes concern. In the second, it describes bright colours. Neither example is necessarily about counting things: the focus can be on importance or how much something stands out.
Predominate is usually a verb. Use it to say that something is most common or has the greatest influence. Like other verbs, it changes form to match the subject and tense.
- Older buildings predominate in the town centre.
- One opinion predominated throughout the discussion.
This verb normally does not take a direct object. You can add a phrase with in or among to explain where something is most common.
You may also encounter predominate as an adjective. That use is established but much less common; predominant is generally the clearer choice for ordinary descriptive writing.
When editing, check the job the word needs to do. Describing a concern calls for an adjective; saying what dominates a discussion calls for a verb.