I used to teach 2 different kinds of student. One group were kids and adults with learning difficulties and some with behavioural problems. The local secondary school didn't know what to do with them, nor did social services, so they were sent to me and a colleague at the college to "learn" IT skills. We were never given training or advice nor were we given information on their level of ability. Basically, we were babysitting because they were never expected to learn anything. However, I discovered that it was possible for some of them to learn little bits and perform quite well at office tasks, only to be asked by the (then) Director of Education, "Why are you bothering? They are unable to learn."
The 2nd kind of student consisted of adults who had never achieved anything at school and school leavers who, for whatever reason were not ready to go into the workforce. I often had to wait a long time, going over and over the lessons but eventually there would be that moment when I could see the light dawning. That was why I did the job. They had been assumed by the school to be "sows' ears" but when they left us, as "silk purses", they had GSVQ/HNC/HND and a few moved on to degree courses. All were eminently employable.