VFE
Although it isn't taught as part of the PPL course my CFI told me to show a student what the stall is like. Here is why.
The stall scenario is on the approach to the runway. Flaps, medium power setting and pulling too hard. On the PPL and CPL you recover at the incipient stage, ie buffet or stall warner.
However if you take the aircraft further into the stall then it could depart into a spin or a spiral dive. The wing drop is very marked. (As I found out on my mutuals).
It is very important to show a student why we recover at the incipient stage.
I have been led to believe that the Cessna that crashed and killed a young lad on a solo flight in the summer was caused by the A/C departing controlled flight.
If an instructor is worried about flying the sortie, ask for a demonstration from the CFI it may save your life.