 Re: in a few days vs for a few days
Sentence 1 is strange. The meaning is "I will finish the essay" so it would be more natural to use that verb: I will finish writing the essay in the next few days. i.e. you're near the end with only a bit more work to do and some time today, tomorrow or the next day will be able to hand it in.
Sentence 2 is fine. The meaning is : I'm going to take a break from writing the essay today, tomorrow and the next day and will start working on it again the day after. |