This police force became important in the 1800s.

Is the subject of the sentence police force or force?

Also,

Mounties have become an important part of Canadian life.
What is the PN or PA of the sentence? Is it PA = important?
Or PN = part?

3 answers

1. Either "police force" or "force" could be the subject here. Because "police" isn't capitalized in this sentence, I'd use just "force" as the subject, though.

2. PN — "part"
("important" would be the PA if the sentence read like this: "Mounties have become important in Canadian life." But you can see it isn't!)
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