The same caveats apply as before: this is a class in the history of the English language and therefore dates--at least approximations--do make a difference. When formulating answers, always consider the significance of the question in the context of the history of the English language and its relevance to that context.
Think comparatively and hierarchically: what differentiates Middle English from Old English? What are the differences in structure (grammar)? What other kinds of changes occur? What are the external causes of some of these changes? What are the significant historical events that contribute to linguistic change in the Middle English period? (e.g., What was the Norman Conquest? When did it occur? Who were the Normans? What is the linguistic significance of this event?) Be prepared to identify the features that mark the language of Middle English texts as being Southern or Northern. From which variety of Middle English do modern standard British and American English descend and why?