some language schools have a high staff turnover

Yes, i think you're right. When you think of this in regards professional development or the lack of if it becomes a bit of a chicken and egg scenario.

Do teachers leave because they don't get training and support?

or

Do schools not provide training and support because teachers leave?

Something for any school administrators/owners to consider.

It's also my observation that those schools that are successful and better places to work are reliant on key members of staff who consistantly go above and beyond their position. Now it might seem obvious that an organisation needs good employees but it also needs a set of principles, procedures, professionalism and a general structure to underpin everything - many language schools don't have these! It means when experienced members of staff leave they struggle to cope and fill the void as they were reliant on the individual not the system. I think you can often see evidence of this kind of thing on this board when people write that "it was good 6months ago" or "i worked there in 2010 and had no problems", etc, etc.

Having an established system doesn't necessarily mean that teachers won't have the flexibility to do what they want and what's best for their students. Quite the contrary, it often provides the necessary support and environment that teachers need in order to be creative and spend as much time focusing on the development of their students rather than fighting the good fight against an entirely unorganised and unstructured administration. I wonder how many hours of teachers lives both professional and personal have been wasted and what the knock on effect to students is as a result of all the **** systems that exist out there - worrying!