I was always taught that using a verb that implies movement automatically tiggers the accusative case for the direct object when used with certain prepositions.
For example, Germans say
Ich gehe ins Bett.
Ich gehe im Bett.
However I'm confused by exactly what degree of movement needs to be implied for this to hold true. Is there some kind of threshold that needs to be reached?
For example, let's take the sentence
I look at the clock.
Would that be dative or accusative? To me it doesn't require a great deal of movement, but then I suppose you are moving your eyes. Is there a list of not quite so obvious verbs that also require the accusative?