(B) the cold reality is that they need to learn the rules of "correct" English, even those rules are often arbitrary. That's because in professional situations, others — including but not limited to hiring partners, clients, and referral sources — are likely to think less of them if their usage doesn't conform to those rules; and
(C) When grading their work, I will deduct points when they don't use "correct" English, because part of my job is to help them learn to do so.
(A) [as stated above];
(B) the cold reality is that they need to learn the rules of "correct" English, even those rules are often arbitrary. That's because in professional situations, others — including but not limited to hiring partners, clients, and referral sources — are likely to think less of them if their usage doesn't conform to those rules; and
(C) When grading their work, I will deduct points when they don't use "correct" English, because part of my job is to help them learn to do so.