I was reading some Spanish grammar stuff, and it mentioned the word "cuyo" as basically meaning "whose". I've literally never heard of this word before, and I've studied Spanish since middle school and even spoken it with people conversationally, so I'm very confused.
It seems like this would be a really common word, but I swear I've never encountered it before. Is it regional, or rarely used, or have I just managed to overlook it for years?
"¿De quién es este?" works better, "¿De quién es esto?" works best because esto is the word you use to mean an object you're directly referring to in general while este is more for when there are multiple objects and you want to refer to an individual one. There might be a better way to explain the grammar behind it but that's the general rule for conversations.