However, it's possible he had some exposure to languages through his extensive travel and interactions with scholars from different countries. He spent time in Europe and interacted with European intellectuals during his career.
It's also worth noting that the focus of Dewey's work was on philosophical and educational matters, rather than linguistics. Therefore, even if he had some knowledge of foreign languages, it wouldn't have been central to his academic endeavors.
In conclusion, while we cannot definitively say John Dewey was fluent in any foreign languages, it's also impossible to rule out some level of exposure and understanding.