How to say in Czech: How good is his Slovak?

English
How good is
Czech
Jak dobře umí slovensky?
His Slovak is getting better.
His Slovak is very good.
How do you say that in Slovak?
I do not speak Slovak very well.
You speak Slovak very well.
His native language is Slovak.
Is he learning Slovak on his own?
He is learning Slovak.
He is not Slovak.
He is Slovak.

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