Yes, you use <em>so</em> before s, z, š, ž and even some consonant clusters, eg. <em>so mnou</em>.
It really is about the easiest way to say it all together. :)
Well, yes, this is the same what I have learend. But žena starts with ž not z.
Does it mean that ž and z are equal from this point of view?
,,So ženou." To je ľahšie vysloviť.
You say "so" or "zo" when the next word is starting with "s" or "z", so you can say it easier.
so ženou