The last words of Julius Caesar are often quoted as Et tu Brute?, “You too, Brutus?” They are also quoted as Tu quoque, Brute?, which means the same. The second variant has been sufficiently popular to make logicians apply these words to a well-known logical fallacy (“pot calling the kettle black“).
That those famous last words are quoted in two versions, already suggests that something’s gone wrong. They cannot both be correct. As it turns out, the expression “Et tu Brute” has been coined by Shakespeare (Julius Caesar, act 3, scene 1); they are not the dictator’s final words, though, because he reflects upon his own death in characteristic third-person, “Then fall, Caesar”.
That leaves us with Tu quoque, Brute. But Caesar probably did not even say that. According to Suetonius, he just sighed, or said something in Greek:
When he saw that he was beset on every side by drawn daggers, he muffled his head in his robe, and at the same time drew down its lap to his feet with his left hand, in order to fall more decently, with the lower part of his body also covered. And in this wise he was stabbed with three and twenty wounds, uttering not a word, but merely a groan at the first stroke, though some have written that when Marcus Brutus rushed at him, he said in Greek, “You too, my child?” (καὶ σὺ τέκνον;)