"Kolik má ten dům koupelen?"

Translation: How many bathrooms does that house have?

[BelindaJua1]

why is it not koupelny here?

[endless_sleeper]

You need genitive plural here.

[BelindaJua1]

Thank you! Is it because of kolik?

[VladaFu]

yes

[GuyLearningCzech]

Would it be wrong to word it like this: Kolik koupelen má ten dům?

[VladaFu]

No, provided you correct the *kolek -> kolik.

[GuyLearningCzech]

LOL. Sorry about that. Will do—thanks!

[Tom307502]

Just wondering why the verb is placed here. My inclination would be to put "koupelen" immediately after "Kolik".

[VladaFu]

Both orders are fine. There may be a very subtle difference in the preference for these two but that would require some difficult research. You can treat them as equivalent.