"Hamburg is by the water."
Translation:Hamburg ist am Wasser.
We say cities are "am Wasser/Fluss/See/Teich"(=water, river, lake, small lake) and "am Meer, an der See" (sea, sea) when they are "near, by or nearby" the water. "an" is the normal preposicion for this.
- Hamburg ist an der Alster. Hamburg ist am Wasser.
- Köln ist/liegt am Rhein. Berlin ist/liegt an der Spree.
is the such a word as "ams" to be preceding a neutral word (such a wasser)?
am is a contraction of an + dem, i.e. the preposition an and the neuter or masculine dative article dem.
If you contract an with the masculine accusative article das, you get ans, e.g. ans Wasser "to the water" (indicating the destination of motion, rather than a location).
ams does not exist; that would be *an + dem + das" with two articles in different cases and make no sense.
but why is this dative? there is no movement so shouldnt it be accusative
An, in and auf are more complicated: in some verbs, they trigger the accusative, in others the dative. You'll just have to memorize these. Er denkt an seinen Bruder. (He thinks of his brother.) Er arbeitet an einem Film (He's working on a film.)