Intensive care

The first word on this list comes with a preposition that surprises English speakers. A patient lies im Krankenhaus, in the hospital, because a hospital is a building; but a ward is treated as a surface you are on, so the same patient lies auf der Intensivstation and is moved auf die Normalstation. The case follows the ordinary rule for two-way prepositions: dative for where someone is, accusative for where someone is going, which is why a transfer is always auf die Intensivstation. Staff then shorten the phrase in two steps: er liegt auf Station has lost its article, and er liegt auf Intensiv has lost the noun as well. Both belong to speech and handover; a discharge letter writes the full form.