I did a large number of the Language tests in South Africa specifically for the ATCs here and was supprised to find out a very similar situation with our ATSA and Cadet scheme students.
I even came across a number of candidates who were terrified of flying (yet chose to take a job in aviation.) The one test had to be aborted due to the candidate still being in a state of shock after being flown from her unit to the testing station for th test. The flight was a normal flight yet sh was errified of flying that she could not test afterwards.
The fun part was picking out the mispronounciations especially on Fuel and we got many different variations of the word.
The controllers were generally up to date on the knowledge requirement and this was clearly adressed in the OJTI at stations however overall basic knowledge was definitly lacking from ab initio students and young ATSAs and I felt that this was not sufficiently dealt with at the training acadamy stage. Most students were also too afraid to ask what certain terms meant and would rather try make a guess than find out.
Interesting I found that even with some controllers the term Wake Vortex was not always understood but Wake Turbulence was.
In most cases we would try educate a bit after the test however not posible if a lot of general knowledge was lacking.