Do various language tests
General outer, special inner
The british word colour is written color in american english.
The british word col|our is writ|ten color in amer|i|can eng|lish.
Special outer, general inner
The american word color is written colour in british english.
The amer|ican word color is writ|ten col|our in brit|ish eng|lish.
Unknown subtag
If subtag is unknown we should fall back to the maintag.
If sub|tag is un|known we should fall back to the main|tag.