"My legs hurt after a long walk."
Translation:La kruroj doloris min post longa promeno.
Wouldn't "Post malfacilajn promeno miaj kruroj doloris min" be "After the difficult walk my legs hurt me"?
It didn't accept it in the "Tag all that are correct" version of this question, but if the walk was long enough to hurt their legs wouldn't that count as being difficult and so also be one of the correct answers?
Neither, it's a preposition.