Why plural "you"??
You mean why plural bojíte? Bojíš is accepted as well.
Is is not just the polite form rather than plural?
Could be both.
if "My sister is afraid of mice" is translated as, "Moje sestra se bojí myší", why "Are you afraid of your wife?" can't be translated as, "Bojíš se své ženy?"
Here we have afraid FOR, not afraid OF. Please do read previous discussion before asking like this. See the answer by Jamie08MD.
Oh, sorry! I didn't notice it was "for" in the English sentence, and thought the other person was simply asking how to say that. Thank you very much for the reply!
Later on there is also a sentence, "Bojím své manželce" which is translated as "I'm afraid of my wife". So why Genitive without a preposition can't be used here?
"Bojím své manželce" is not Czech.
can someone tell me the difference when to use "zeny" or "manzelka"?
(sorry - no accents on my computer)
In this context they mean the same.
In other context žena is a woman, a female human, manželka is always a wife.
jsi se o svou manzelku bojis?
Something wrong with this? Reported.