I had to laugh at the new U-CAN CM (mail-order home study courses) for
their new textbook free (Pimsler?) English course. The only phrase in
English you hear is the above, "Do you understand Japanese?" which of
course (a) negates the point in learning all this gaigingo, and (b)
it's not even "Can you speak Japanese?", as if actual communication is
not the object of the exercise.

Ken