We were kindly invited to one of my student's marriage ceremony in French in Neuchatel where she married an American from New Jersey. Midway through the ceremony, the celebrant suddenly turned to him and said in French " do you understand"? to which he replied "Yeah.................I think so". Everyone smiled and the ceremony continued.
Great! I will make sure that I'm able to differentiate "do you understand?" and "are you pretending be understanding?"