nots tumbles it

Topic, theme, and subject: は wa and が ga

A common linguistic joke shows the insufficiency of rote translation with the sentence 僕は鰻だ boku wa unagi da, which per the pattern would translate as “I am an eel.” (or “(As of) me is eel”). Yet, in a restaurant this sentence can reasonably be used to say “My order is eel” (or “I would like to order an eel”), with no intended humour. This is because the sentence should be literally read, “As for me, it is an eel,” with “it” referring to the speaker’s order. The topic of the sentence is clearly not its subject.