Or, perhaps the person thinks (solves) in abstract concepts rather than linear words. Just because many people mouth words when reading or can't think without hearing words in their head or aloud, doesn't mean others should have to handicap their own efficacy of thought while working it out. Two conceptuals can communicate in a kind of ultra condensed shorthand liner verbal thinkers struggle to follow. Less can't communicate, more can't conceptualize squared off with can't verbalize.
Both groups should synthesize simply and clearly at the end, both should work to get in sync. And both ways of thinking have their uses in a team. Catch: conceptual thinkers can interview verbal thinkers, the other way around is more challenging.