Is that pronounced “peace” or “piss”?

More like pi+[y]es, but single syllable and no y.

As an American, I hear “pyes” - a single syllable “yes”, with a preceding “p.”

otterley 7 hours ago | parent | prev [-]

When do you use that vs собака (sobaka)?

	▲	throw_a_grenade 7 hours ago \| parent [-]
		I don't, I'm Polish. Can't say for sure for Ukrainians, don't know Ukrainian that well, but my reading of https://en.wiktionary.org/wiki/%D1%81%D0%BE%D0%B1%D0%B0%D0%B... and https://en.wiktionary.org/wiki/%D0%BF%D0%B5%D1%81#Ukrainian suggests that пес must be male, but собака is either male or female. I might be wrong.