At the pharmacy

An English speaker who wants to say « dose » reaches for die Dose, and has just asked for a tin. Die Dose is the can of lemonade, the tin of biscuits, the pot of face cream. The amount of a medicine is die Dosis, and every compound on this counter is built on that form: die Einzeldosis, die Überdosis, and on this list die Tageshöchstdosis. The verb and the noun for the act follow it as well, dosieren and die Dosierung. The trap closes in the plural, where the two words turn into one: the plural of die Dosis is die Dosen, exactly the plural of the tin. So zwei Dosen am Tag is two doses a day on a package leaflet and two cans a day in a kitchen, and only the sentence around it decides. In the singular there is never any doubt, which is where the word is safest: say die Dosis, and keep the s.