Well, English, obviously.
The Big Bang Theory Season 12, Episode 14
English - SDH
The Big Bang Theory Season 10, Episode 10
or possibly penguins,
her English is atrocious.
The Big Bang Theory Season 10, Episode 6
English - SDH
The Big Bang Theory Season 10, Episode 13
Fine, I'll do it in English,
The Big Bang Theory Season 5, Episode 24