Use a Romanian word and make it sound kind of English to make a point
Eg: “I gătated dinner” - ‘a găti’ = to cook -> I gateted dinner ~= I cooked dinner.
This is a bad example because it’s not really used, most people know the ver “to cook”, but you hopefully get what I’m explaining.
In this context, ‘a inunda’ is a verb in Romanian, it means “to flood (something)”. If you’re Romanian and you don’t know the word exists in English, ‘inundated’ sounds like one of those made-up “verb+ed” constructions.
So while it’s a silly question for someone who doesn’t know Romanian, it’s also a valid question for someone who has heard these types of bad constructions before, and has never heard of the English verb “to inundate”.
Hopefully the guy’s reply makes a bit more sense now, I don’t think it was actually meant as an insult tbh (☞ﾟヮﾟ)☞