Words like kio, tio, io, ĉio, etc, are all regular. Check them out here: https://en.wikipedia.org/wiki/Esperanto_vocabulary#Correlatives
It says that 'tio' means this or that. I put 'this' and it called it wrong. Should i report this or am i missing something?
Since Esperanto Correlatives don't get the plural -j, could this also mean, "What are those?" or by that sense, "What is this?"