How to say in Czech: They speak Japanese fluently.

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

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.