I would say the answer to that, for the most part, is a cue card. All of our officers have cards on which the right to counsel, the right to be advised of the right to counsel, and so on are written in English on one side and French on the other side.
This gentlemen or this lady may have never spoken any other English in her life. That may be the only English she speaks, but it's sufficient for the accused to understand what his rights are.