All the schools I have worked in have a behaviour policy and they also have a Learning Support department. If a pupil has been diagnosed with a specific developmental disorder at Primary School, this pupil will normally get support in High School too, particularly in the first year. However, if a child has not been diagnosed beforehand, it can take a long time before steps are taken to investigate the child for possible disorders. Behaviour tends to vary from subject to subject, from teacher to teacher and from class to class (where subjects are set according to ability). Depending on the school, teachers can record poor behaviour on programmes, such as OTB. Some schools have no facilities to centrally record behaviour issues and so these may not get picked up quickly, say by guidance, pastoral care or by SMT. In other schools, there is such a wealth of information recorded, that nobody reads this regularly or often enough, so action is not taken quickly.
Due to lack of funding the extra support in schools is diminishing. In my opinion ongoing poor behaviour should always be investigated and ideally the appropriate kind of specialist support given. I know full well that for some pupils having to learn modern foreign languages is extremely difficult, but the support given to this particular subject is minimal compared to certain other subjects. There are simply not enough staff to go round. To set specially differentiated work for these children, who are normally not set in ability groups until second year, without additional support of an assistant, who can then work with and supervise these pupils, is almost impossible, as there are often also very bright pupils, who need to go forward and get extra challenges, in the same class.
The last school I have been working in has set pupils in ability groups from year one and this makes a huge difference to their behaviour, as they can go at their own speed, we can do lots of games on the smart board and keep repeating concepts in different ways where needed, or speed up where this is appropriate to the level of the group. I was also lucky to have had a lot of these pupils on supply in English, before taking them in German. This gave me an insight in their overall ability, what they reacted like when faced with writing in English, listening to a story, discussing a passage we read together or doing work independently. In English these pupils had learning support assistants, but not in German. Their behaviour however was mostly fine, as they were confident that they could do the work set, unlike pupils in mixed ability classes I have taught in other schools.