# an vs. auf Boden, Wand, Decke

I recently learned that you put a picture "auf" the floor/table, but you put it "an" the wall.

One explanation was the horizontal vs. vertical orientation of the surface. But how do you say "I put a picture on the ceiling"? I don't mean that I painted it directly on the ceiling ( I'm not Michaelangelo ;)

What about something that never relies on gravity, like a sticker? "I stuck the sticker on the floor/wall/ceiling". I'd live to hear the intuition for resolving ambiguous situations.

• I think these rules are based on not-so-logical collocations. In Austrian German, I'd say you can use auf for everything. – phipsgabler Oct 25 '19 at 10:04

The more I think about it, the more complicated it gets.

My first guess was that auf would be used whenever something approaches the surface from "above" or someone looks at it from "above", whereas an would be used whenever something approaches from "below" or the "side" or someone looks at it from "below" or the "side". The following examples seem to support this:

From "above":

• Sie malte ein Bild auf den Boden.
• Er legte das Foto auf den Tisch.
• Der Vogel landete auf dem Dach.

From "below" or the "side":

• Sie malte ein Bild an die Decke.
• Er klebte das Foto an die Wand.
• Der Vogel landete am Giebel.

These examples invalidate the vertical-versus-horizontal hypothesis.

But then I realized that my guess is invalidated, too, by examples such as these:

• Sie sprühte etwas auf die Wand. (also possible: an)
• Er blickte aufs gegenüberliegende Haus.
• Der Vogel flog auf mich zu.
• Ich fand den Schlüssel am Boden.

Therefore, I am afraid that no satisfactory answer with clear rules can be given.