I can speak Esperanto like a native.

On its face, the line is a boast about linguistic mastery, but in Milligan’s comic idiom it reads as a self-undercutting joke. Esperanto is a constructed auxiliary language with comparatively few “native” speakers, so claiming to speak it “like a native” plays on the mismatch between the phrase’s usual meaning and Esperanto’s unusual sociolinguistic status. The humor comes from the deadpan confidence of the claim and the implied absurdity of measuring authenticity in a language designed to be neutral and learned. It also fits Milligan’s broader tendency to puncture pretension and to treat language itself—its rules, labels, and social signals—as a playground for nonsense and paradox.