Can anyone be coached?
In the ideal training world we would be able to coach everyone, but in reality coaching is not actually suitable for all.
On the diagram below you can see the skill vs. will theory which demonstrates that an individual will need to have enough knowledge/skill of what they are being coached on to be able to come up with their own answers and also a certain level of will to want to be able to do it, otherwise it will prove difficult in engaging them. Coaching only works if the person has the desire to improve. You can still coach people at the low skill/high will level if they can bring with them transferable skills - although a mentoring approach may be more appropriate.