Complex sentence: Since the 1970s, colleges established in Lakota reservations have taught to write Lakota to their students according to that individual reservations' variation of the language, therefore orthographic rules and even pieces of the alphabet vary amongst the Lakota people themselves.
Split into simpler sentences: Since the 1970s, tribal colleges established on Lakota reservations have taught written Lakota to their students according to that individual reservation's usage. Therefore orthographic rules and even pieces of the alphabet have varied amongst the Lakota people themselves.