
This is an archaic usage. If it is not a deliberate usage I would suggest "Art thou" be changed to "Are you"

It is deliberate; the Esperanto uses a word called "ci", which is almost directly equivalent in terms of both meaning and lack of use.

I guess this depends on whether the Esperanto expression sounds equivalently ridiculous.
The English is an incongruous mix of archaic and contemporary forms, therefore it's facetious at best. You wouldn't teach a new student to speak this way, not in any language.

->
Are you being serious?

I'd suggest deleting this one and linking the Esperanto to the already existing English sentence, assuming it matches.
[#1065431] Are you being serious? (CK) *audio*