Write an overview of the English language history from Old English to World Englishes, focusing on distinctive morphological/syntactic (grammar) features of different eras, which demonstrate the developmental direction of changes in English from a synthetic to analytic language*. That is, use the evolving of English from a synthetic to analytic language as the leitmotiv/trend for framing your answer.
Provide examples to support your descriptions of changes and development, and explain internal and external factors for such changes and development. Remember that you are not expected to write an exhaustive book of the English language history, but a selective, concise summery of it, in order to construct your own narrative of how English has evolved over time.
You need to provide the sources of the details you present: if they are from McIntyre (the textbook), provide page numbers; if they are from other sources, provide them in the reference list.