Which country does not speak German as a mother tongue?

The question is a bit tricky! While many countries have German as an official language, no country has German as its *sole* official language.

Here's why:

* Germany: German is the official language, but other languages are spoken within the country (like Turkish, Polish, etc.).

* Austria: German is the official language, but other languages like Hungarian and Croatian are also spoken.

* Switzerland: German is one of the official languages (along with French, Italian, and Romansh).

* Liechtenstein: German is the official language, but other languages like Alemannic and Swiss German are also spoken.

So, technically, no country has German as its *sole* mother tongue.