We have been reporting on Cortana travel reminders popping up in a wide variety of languages recently.
MicrosoftInside.es have managed to figure out what’s going on. Apparently the language of the reminder depends on language set in the Regional Format in the Region setting.
They demonstrate the “hack” in the video above and note in works for a wide variety of languages. It is of note however that this did not used to work, showing that changes are indeed afoot with Cortana.