Dear R.B.,
Some developmental disorders which affect language development also specifically affect social development. This is certainly true of the autistic-spectrum disorders. A web search will yield more information on these conditions.
Language difficulties in themselves also influence our ability to comply with social rules. For example, if rules are presented in words, the child might not fully understand. Or the child might not apply general instructions to specific circumstances.
I suggest you use the speech/language pathologist(s) who know you son as your resource. They should be able to help you with specific instances of what your son finds difficult, and how that might affect his ability to meet expectations for social behavior. In addition, make note of specific instances yourself, and use them to explain your point to the principal.
Regardless of what 'label' a child carries, it is important to help him develop what he specifically needs-- and to do so without making him feel helpless in the face of his difficulties. Rather than hit him with infraction after infraction, perhaps it would be better to teach the desired skills, one category at a time. Teach through action in various circumstances, as well as words. Then hold him responsible for skills he has learned.
Best Wishes,
Ruth Alice Jurey, M.S., C.C.C.
Speech/Language Pathologist