How to say in Czech: They speak Croatian fluently.

English
speak fluently.
Czech
Oni mluví plynně chorvatsky.
Do they speak Croatian?
They do not speak Croatian.
They do not speak Croatian very well.
They speak Croatian.
They speak Croatian very well.
They speak only a little Croatian.
Does anybody here speak Croatian?
Are they Croatian?
Are they learning Croatian?
Are they learning Croatian 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.