Grammar is definitely important, however being preoccupied with grammar when learning a language can lead to what in golf is called "paralysis by analysis." A truly solid golf swing takes years to build. To do so successfully, one has to painstakingly build each fundamental into the swing, one at a time, until it becomes second nature. When watching an accomplished golfer, it is obvious he or she is not focused on all of these fundamentals, but rather on visualizing the shot and capturing the feel to pull it off. To use this analogy I see grammar as the fundamentals, and the shot execution as actual communication. With that idea in mind when teaching conversation I focus on one grammar point, review it, and do some very structured drills to reinforce it. After that I move on to a much more communicative activity aimed at augmenting fluency.