I know by experience that many students start with a bad representation of what they should do during their classes. In fact, there’s a common misconception about language learning, that it’s mostly about memorising vocabulary and expressions. Surely this is a part of it, but in order to be able to express themselves accurately in French, the students will need to figure out the logic of the language, integrate its syntax, the way the words combine with each other, in which order, how do they interact, etc. Students can always discover all this by themselves but that’s where a teacher’s help can benefit them most (this and pronunciation, which is also difficult to crack all alone). Years of terrible language teaching in schools can leave students with the wrong expectations about what they need.
What would they have a hard time acquiring without me?
During a week, the student has a limited number of hours he can dedicate to learn French, and even less to spend with a teacher. And since they generally need to pay for the classes whereas all the autonomous work can be done for free, it sounds like a good idea to optimize the time spent in the classroom (or on Skype, or with the tutor, etc.). Basically, the teacher should make them work on what’s harder for them to do without help, and what’s really going to make them progress faster. Learning vocabulary is one of the things that can easily be done without much assistance, and the best thing a teacher can do about it is providing advice to optimize the process. Unfortunately, most teachers use a lot of the class time to “teach” vocabulary, either because it’s the easiest thing for them to do or because they genuinely believe it’s what their students need.
I believe it’s basic teacher ethics to make sure the students take the best benefit possible from their classes. Then they can use the rest of their available time during the week to do activities that won’t require direct help. They can spend one hour listening to a Youtube greetings video, taking notes and rehearsing it by themselves, or the teacher can spend a whole lesson on this: basically they’ll get the same result. I’ve done it a few times at students’ requests and I felt I was being dishonest by wasting their time and money with things they could easily achieve by themselves. Now I reply to such demands by providing them with links, advices and resources so that they can work efficiently on it and make better use of their class time.