I would like to know the reason why.
NOT A TEACHER
(1) I also would like to know.
(2) I have checked my books, and none of them had "the" answer.
(3) My books tell me that we have this choice:
(a) I hope (that) you may get well soon. (modal)
(b) I hope (that) you will get well soon. (for the sake of simplicity, many books refer to this as the future tense)
(c) I hope (that) you get well soon. (present tense)
(4) My books tell me that 3a is the most formal. Of course, I do not know, but probably few native speakers in 2011 speak/write this version. But it is rather elegant, isn't it!
3b is certainly correct.
3c is, as the other posters have said, probably the most common. Why? Well, as
one poster suggested, people speak fast. Why say "I hope that you will get well
soon" when you can simply say "I hope you get well soon"?
(5) When you speak English with native speakers, you might consider using 3c. If
you use 3a your listener will find it rather unusual; if you use 3b, your listener may
consider it a bit formal since most (?) native speakers are accustomed to hearing
3c. When you speak English, you want your listener to pay attention to your ideas;
you do NOT want your listener to be distracted by your grammar. For example,
"correct" grammar is "It is I," but since most (almost all?) native speakers nowadays
say "It is me," if you say "I," your listener may stop paying attention to your ideas and
start paying more attention to your grammar. (In fact, nowadays many native
speakers now think "It is I" is wrong!)