(A quiz had been taken ...)
Half an hour later, Lockhart collected in the papers and rifled through them in front of the class.
"Tut, tut -- hardly any of you remembered that my favourite colour is lilac. ..."
I'm not sure why 'in' is there. 'Collect' can be used as a transitive verb, so I think "collected the papers" is good enough. Why does it put: "collected in the papers" instead. Is there any difference between "collected the papers" and "collected in the papers"?
-- From Harry Potter.
I suppose it can be considered a phrasal verb, like "brought in", "washed in", "blew in", used to emphasize the general inward motion of the objects.
Coming back from her morning walk, she brought in the early post and placed it on the table in the kitchen.
That being said, it's not a phrasal verb I'm familiar with. I agree it seems redundant since "collected" already implies "toward the person doing the collecting." Perhaps this is simply Rowling's personal style, or possibly more familiar to her BrE dialect.
Also, it's possibly that most native speakers -- including Rowling's editors -- didn't even notice the "in" in the sentence, since it's not expected and adds no additional information.
