Possible Duplicate:
Should I use “will” or “would” when I suggest that something will/would come in handy?
For example:
Tom: Hey, will you be free tomorrow night to catch a movie together?
Jane: That will be great! / That would be great!
Often I see no difference. Yet one day it occurs to me that saying "would be great" sounds less certain than does "will be great". I was wondering whether this reply indicates that Jane cannot guarantee that she will make it tomorrow? Or is it totally out of politeness to say so rather than "will be great"?
