you can't... sorry
you can just teach it the words you prefer it to suggest by accepting the words it suggests or changing them.
You don't need to hit the x, just anywhere on the word.That sucks, my main language is spanish and when I write a word in spanish is always replaced by another word, if I turn the spanish language ON, then the english words get replaced. . I think I found the first think I hate about the iphone . They could make the X a little larger
Hopefully a update will get us the option of removing that feature. Blackberry and Pocket PC have the option to turn it off
with a jailbroken phone you can get rid of it. i personally like it so i'm not getting rid of it.