How to say in Czech: They speak Polish fluently.

English
speak fluently.
Czech
Oni mluví plynně polsky.
Do they speak Polish?
They do not speak Polish.
They do not speak Polish very well.
They speak only a little Polish.
They speak Polish.
They speak Polish very well.
Does anybody here speak Polish?
Are they learning Polish?
Are they learning Polish on their own?
Are they Polish?

Czech phrasebook and translator with tens of thousands of sentences translated by humans. Czechslator is being developed by Michal Měchura. CREDITS Czechslator's sentence generation engine is partially based on Grammatical Framework. All Czech pronunciation is computer-generated using Microsoft Azure Text to Speech. When Czechslator cannot find a translation in its own database, it looks in the PanLex dictionary or obtains a machine translation from Microsoft Translator. PRIVACY Czechslator does not save any cookies in your web browser and does not collect personally identifiable data. Czechslator uses StatCounter for traffic analysis, configured not to save any cookies in your web browser and not to collect any personally identifiable data.