Absense

there was a teacher at my old school who knew two words in english: "yes" and "no" so the only thing he would say to me was "yes" or "no" in response to something i said to him in perfect french.
AS IF I DON'T KNOW HOW TO SAY YES OR NO IN FRENCH.
does this also shock and amaze you?
it should! here's why:
-the assumption that if he said "oui" I would not understand and look to him, quizzically.
oh là là