The Essentials lesson in Cantonese contains the words
, which are supposed to mean “Yes” and “No”, respectively.
These choices make me question whether anyone who actually knows Cantonese was involved in creating the course. The two expressions in question are from Mandarin Chinese, and are not used at all in natural spoken Cantonese. They are used in song lyrics, where the composer wants to sound literary. In addition, when a Cantonese speaker reads aloud a text written in standard/Mandarin Chinese, they have to have some way to actually read what is written rather than translating the text into Japanese, so they would indeed pronounce the characters in the way taught in the lesson. But these expressions have no reason at all to be included in a Cantonese lesson, except at the very highest level, where you want people to be able to read aloud in Cantonese a text that was written in another language for China-wide consumption.
If I can spot such basic problems in a language I do know, I am led to wonder what errors there are in courses in languages I don’t already know, which risks damaging confidence in the whole enterprise. What is the general approach taken? Is it first of all to create as comprehensive a selection of courses as possible, and then to go back and improve them? I can understand that—after all, it’s probably better to have an imperfect course than none at all—but, if so, it may be advisable to give learners an indication of how complete each language course is.