"Sut y gelli di wybod fy mod i wedi dweud celwydd?" "how can you know that I have told lies?" "Mae celwyddau, fy mhlentyn annwyl, i'w cael ar unwaith" "Lies, my dear boy, are found out immediately" "Yn y byd hwn mae dau fath o gelwyddau" "in this world there are two sorts of lies" "Mae yna gelwyddau sydd choesau byr" "There are lies that...