Sometimes I find it hard to see the difference between FOR and DURING.
For example: Last week , I was sick during/for 3 days. Can we use both?
Last week, I was sick for (a period that lasted) 3 days.
You use during to describe something that happened at some point between 2 other points. For instance:
During May, I was sick three times.
So on three occasions, between May 1st and May 31st, I was sick.