The question regards the phenomenon where a user can switch context on the same tool seamlessly, and as it seems without thinking. The only practical use of the phenomenon that I know of is the switching of input languages on the same keyboard, but there are probably other real world examples.
Often these users don't type the way I do (looking at the keyboard), still they are very skilled in both Swedish, English and Icelandic keyboard setups. Is this a kind of automated process, such as the use of a piano from a professional concert pianist who does not need to think, only play with what is learned from hours and hours of exercise? I believe it is related. but not the same.
I'm asking of what this mechanism of switching context is and why it works seamlessly for users.
An image of the Icelandic keyboard setup:
Image from http://farm8.staticflickr.com