I don't understand the structure of this... Kia should be "what kind", "what type", right? For instance, "what kind of couple is that?" = "kia paro estas tiu?", so for me it would only make sense that "kia bela paro" means "what a beautiful type of couple" - the kind of couple is beautiful, not necessarily the couple itself (though the first might imply the latter). On the other hand, I wouldn't know exactly how to say "what a lovely couple" --- "kio bela paro!"? I'm super confused =(
It's an emphatic kind of what, not one fulfilling a questioning purpose.
It's like the English:
"What a load of rubbish!"
"What a beautiful poem!"
"What a stupid thing to say!"
The clauses above aren't interrogatives (questions) even though they're headed by the interrogative pronoun (what ). They're declarative statements, where what places emphasises on whatever follows.
Strange. I would have expected "couple" to have better esperantan type word structure, incorporating the concept of 2 and making it into a noun. .. "duo" springs to mind for some reason.
In this case, I think the word comes from the English word "pair". Incedentally, Glosbe translates "duo" to mean "couple, pair". So the two words are synonymous.