Warning! Blatant self-promotion ahead!
I posted this answer: https://ell.stackexchange.com/a/225606/9936, and the question was since marked as a duplicate. My answer has been well received and I feel that it's better than the other answers on both questions because it explains how the grammar works instead of just saying what's right and what's wrong. Yes, I'm biased, I know!
Can I post the same answer on the original question, or is it better to leave it on just the duplicate, even though the "duplicate question" marker only goes from the second question to the first? Fewer people will see my answer because they'd have to notice the duplicate question in "Linked" at the side where it's not as obvious as "This question already has an answer here:" at the top of the question.
As you can see in the screenshots, on my very big full size screen, no linked questions are visible until the user scrolls down.