As for the gender of river names, the most important rule in German is that there is no rule – unlike, for example, in Latin, where the rivers are basically male, where the Danube is also called “Danuvius”. In German, gender depends on several things.
Pay attention to the ending
For once, whether there is perhaps another word in the river name. For example, many rivers end here in southern Germany on “ach” like the Schwarzach, the Wutach or the Salzach. They are female because the oh is an old German expression for river. The Schwarzach is nothing else than the black river. The Danube is similar: it has the same roots as the Russian Don river, namely the Indo-European word “Duna”, “river”. And the Don floodplain is the floodplain of the river. And because the floodplain is female, so is the Don-au.
Celts, Romans, Teutons – all left traces
This also shows that the names of our rivers come from very different epochs. Celts, Romans, Germanic tribes – they were all here, and depending on who gave a river its name, the traces of that river have survived. The Germanic tribes mostly gave the rivers female names, the Romans more masculine, because at least the great rivers were often associated with gods.
In the case of the Rhine, it is not entirely clear whether the name, and thus also the male gender, was introduced by the Romans – as Rhenus – or by the Celts before that. It is interesting here that the Rhine probably has the same word root as the French Rhone, namely “rhei” – to flow. The classical philologists among us still know the sentence of Heraclitus: Panta rhei – everything flows. That is obviously the same “rhei” as in the Rhine. It can also be found in the German word “rinnen”, although the Rhine is of course anything but a trickle.
These few examples show that most of our rivers are female, some are male. But there is no clear rule and a lot depends on the historical circumstances of the naming. And sometimes it jumps too: The Rhone is called “le Rhône” in French – so it is male.
Thanks to Prof. Konrad Kunze.