Make it possible to select primary language and have it dominate the suggestions.
I use both Norwegian and English, but Norwegian is my primary language. For some reason English suggestions are preferred over Norwegian, e.g. when I type a small letter i (Norwegian word meaning in) it always autocorrects to the English capital letter I. Either SwiftKey ought to learn that I want small i instead of capitol I 99 out of 100 times or it ought to be possible to select which language is the primary.