I don't know where else to write about the Tips and Notes, so I'm making this discussion. If there is a better place for this, I would appreciate if someone could point me to it.
In the second lesson of "Relatives," the infix "-po-" is used to mean "when," but it is not explained in the Tips and Notes. In the Tips and Notes, it says that "-po-" is one of the locative infixes, which makes sense. I think a description of "-po-" as "when" should be added to the Tips and Notes, especially considering the practice sentences focus so heavily on it and there aren't any sentences for some of the constructions actually mentioned in the Tips and Notes for that lesson.
P.S. I really love the course, and especially the thorough Tips and Notes for almost every lesson. I just want to do what I can to make the course the best it can be!
Edit: I just discovered that "-po-" is explained in the "Advanced Grammar" Tips and Notes. Maybe the exercises from "Relatives 2" should be moved into the "Advanced Grammar" skill.