In short courses or vacation ones I think that speaking is the language skill that should be worked out the most.
However this doesn’t mean that other skills would not be practiced. Usually a class is a span of time where the four skills are practiced: listening, speaking, reading and writing.
Activities and book exercises allow various skills to be used. It is rare that a single language skill be practiced.
A class too is a period where naturalistically those skills are practiced – there is speaking and so listening too, and for example the student has to write down notes whilst listening or speaking.
A class is and should be a period similar to life itself: the key point is communication amid people. / Photo from: students talking in class. 2012books lardbucket org