"When are you going to visit us again?"
Translation:Kdy nás zase navštívíte?
It's Kdy nás navštívíš znovu? It's similar but doesn't sound very natural.
Keep in mind the following:
1) vy vs ty difference
2) znovu/znova sounds more formal than zas(e). Personally, I wouldn't use it with 'ty' but that's more of a personal preference.
3) Moreover, I would place it in front of the verb, sounds better that way.
4) Pay attention to accents.
My first instinct was to use "az" (sorry I don't have a Czech keyboard) here, instead of "Kdy". I read somewhere that "az" is used in reference to the future, and this sentence I think implies the future. Can anyone help me out?