1. What does "to pass back the midterm exams" mean?

2. What does "to run errands" mean? It appears in a sentence that goes like "Sam needs to run errands during lunch".

3. Another one:
WOMAN: Sorry you had to miss the seminar;how're you doing now?
MAN: I took it easy last week-it's amazing what a little rest can do.
It seems that the man just relaxed at home instead of going to school, but it also sounds like that he had very little time to relax, to have a rest, since he said it was amazing what a little rest could do.Then I am confused and wonder if he spent plenty of his time on relaxation. What on earth does the man mean?

Thanks in advance.
Hello fraserpan! How are you doing?

2. "to run errands"...I think it means to do daily routines like to go shopping,to buy small things needed at home or to mail letters, etc.

3. There it's not clear how much time he spent on the rest but we can easily think that the rest he had must have been enough for him.

I'd be glad if I've been of some help to you buddy.I'm not an expert though.Why not look them up in a good dictionary?It sure is the best way of figuring out new or weird things.There are way too many web sources as well.Good luck!
Thank you Bulent.

It does make sense to me with your explaination. Actually, I did look up those confusing stuff in a fairly good dictionary, but sometimes, it's kind of little hard for me to figure out some that you can only understand when they are put in specific occations like sentences. So I think it's a good idea to ask those who are English native speakers. Do you have any specific good idea to help me out by using internet resources or others, buddy?

Anyway, thanks again for your help!