Qué son estos? (for when the objects are close to you) Qué son esos? (for when the objects are not far but not close either) que son aquellos? (when the objects are far) you can say any of these, they are gramatically correct, but it sounds bizarre if you say that. usually, to be specific, we put a sustantive after esto, eso, & aquello to clarify what we are talking about. when you dont know the name of the thing, if its a thing (nonliving and before unknown to you) you can say 'que es esa cosa?' but in spanish we always specify at least if the object is an animal, food, etc. i hope i made my point clear

（plural） you can say ‘Qué son estos'? con “s"

Qué son estos= What are these? Qué son esos= What are those? Qué son aquellos= What are those (over there)? Qué es esto= What is this? Qué es eso= What is that? Qué es aquello= What is that (over there)?