1/2 Language Change Essay Help

[r_may9]

Hey anyone who sees this, for all year 12's i hope your exams are going well! I came here looking for some units 1 and 2 help.
I missed a whole section of the course and as a result i have a lot of knowledge missing. Anyway my teacher before our exam gave us a practice essay question and i wanted to try to do it for some feedback. But the problem is I'm not sure how to go about doing it, specifically what to talk about and where i can find some information such as linguists point of views, to help me write a plan at the least.
This is the topic, and any help would be amazing!!
“The English language has a complicated history, marked by extremes and waves of linguistic exchange.” In what ways has this been true in the development of English? Has it resulted in English being a stronger language? Discuss.
You must make reference to at least 3 subsystems in your response.