How to say in Czech: He is such a stupid boy!

English
is such a
Czech
On je tak hloupý kluk!
He is trying not to be stupid.
That’s a stupid question.
That was stupid of you.
Do not do anything stupid!
I find this whole discussion really stupid.
He is such a brave boy!
Does he know this boy?
What is this boy doing here?
Who is this boy?
Why is this boy here?

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.