What's the difference here - why we use am in one example, and an der in the other?
closed as off-topic by Christian Geiselmann, Eller, Björn Friedrich, problemofficer, Hubert Schölnast Oct 1 '18 at 11:22
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "This site is about the usage and rules of the German language. It is not well-suited to replace a dictionary, thesaurus, or conjugation table. If you have already consulted such sources and still have questions, please edit your question to explain what you found and why it did not help. See this post on Meta for more information." – Christian Geiselmann, Eller, Björn Friedrich
It is because Main is masculine, while Oder is feminine.
Then, an in this meaning is locative (where is it?), so one should use dative.
Frankfurt am Main = Frankfurt an dem Main (because der Main)
Frankfurt an der Oder (because die Oder)
Because in German river names have various genders. Some rivers a masculine, some are femine. So it is
and thus "am Main" (= an dem Main) but "an der Oder".
The declination of "der" and "die" in the case of a Dative case.
"An der" and "Am" are actually Dative (location).
"Am" is, as other mentioned, a composition of "An dem"
So in the masculine case,
the Dative of "der" is "dem"
and in the feminine case, the Dative of "die" is "der" (which is the same article as the masculine nominative)
Sorry, confusing but just the way it is.