I don’t really want to assign a grade to this draft… I just want to sit down with the student and have a conversation about why the words “cannot” and “because” mean completely different things according to context.

“The ice cannot be melted because the temperature is below freezing” uses “cannot” as a physical impossibility  and “because” to introduce a factual reason for the claim, but “The highway cannot be cancelled because one person objected to it” uses “cannot” as a moral imperative and “because” to explain the thing being rejected, not the reader’s rejection of the claim.

Simply giving a mark on the student’s paper doesn’t ensure the student understands why I asked him to consider the ambiguity of “cannot” and “because.”