Student or Learner
Do we still need the word "by" in the sentence below?
"When can you give me a working draft by?"
It would be OK as a sentence without the "by" but there would be a slight difference in meaning.
With the by, the person is emphasising that they need the draft a little more urgently, in my opinion, and without it the question is more neutral.
That's a pretty subtle shade of meaning, though, and either would make sense grammatically and logically speaking.
On a different note, there are people who would hate that sentence for ending with a preposition: it's probably acceptable in spoken English but I might suggest avoiding it in written English - perhaps try "How soon can you give me a written draft?" instead.
Not ending sentences with prepositions is seen as an outdated rule in most modern grammar books but that doesn't mean there aren't still people out there who will disagree, so if it's easy to avoid doing, why not?