"When are they getting married?"
Translation:Kdy se berou?
Not quite. As explained elsewhere by kacenka9,
BRÁT SE means marrying each other. My se bereme (we are getting married = we are taking each other). BRÁT SI is to take something. You can take a cake. Bereme si dort. You do it for yourself, the other party is fairly inactive.
Kdy se berou? - likely asking when the couple is getting married
Kdy se vdávají? - likely asking when the women are getting married to their future husbands
Kdy se žení? - likely asking when the men are getting married to their future wives
OK, that was for learners of the Czech language.
For learners of English: You can probably express all of the above by the same English sentence.