they had split up and he had married so why did he go back to her and why wait a whole year

His first wife died. Maybe he needed time to get over it.

yes of course but wouldnt he have wanted to move on rather than go back to an old girlfriend. I mean after all of that time she could have had a boyfriend

Simple - Michael had other priorities before Kay (ie. the Family).

in the novel Michael tells Kay he didn't get in touch with her before because he never thought she would still be available for him.

In the novel, Michael never did contact Kay, for the reason you give. She contacted him.

I believe for Michael waited a year for two reasons, Apollonia died, and Michael needed to take care of the family and during that time he developed his Don like character more.

I agree w/ Santino-
Michael would have been so distracted with mourning Appolonia (and Sonny), getting the family together again, maybe worrying about getting killed himself, it would have taken a year for his head to clear enough to focus on getting Kay back.

The real question is, why in the world did she take him back?

because she still loved him and he was gorgeous might have had something to do with it lol

Most of the changes in Michael took place without Kay knowing about it, mostly in Sicily. When he comes back, I believe it is only natural that he goes back to Kay. I believe he truly WANTS to make the family legitimate and what better mate than Kay? As for why she took him back, the man she loved disappeared without a goodbye. That makes it almost impossible for someone to move on, since she never had any closure. She wouldn't necessarily understand how he had changed, and still believe that he was like the boy she fell in love with in college.

I think it's because 1. Mourning over Appolonia (sp?) & 2. He was self conscious about his busted up face that McCluskey gave him.

He was self conscious about his busted up face that McCluskey gave him.

I doubt this only because he had the remnants of that broken jaw and still scored appolonia.

I don't think he had any self consciosness about his face or his not contacting her at all.

I think he was deeply focused on his new serious role in the family business, taking care of his father, and didn't really want Kay back in his life yet. She would just be nuisance with the big job of moving out to Nevada. Of course, in the book, when Kay finally does meet Michael, he doesn't refuse to start seeing her again.

It's curious that it's actually Michael who seeks out Kay in the film.

i also think he was concentrating on the family business.after things had settled down he would contact her but he was still griving for appolina