"Která z těch oken jsou vaše?"

Translation: Which of those windows are yours?

[LaynePierc1]

What is wrong with "Which one of those"

[endless_sleeper]

'Která' is the plural form.

If we were asking about a single window, the Czech sentence would start with 'Které...'

And 'which' certainly does not have to be singular.

[vcllist]

"Which of those windows is yours" should be allowed also.