The relationship between these two elements is also asymmetrical. The LANDMARK (the object of the preposition) functions as the stable or fixed reference point for the position of the TRAJECTOR. To put it another way: speakers are far less likely to say the table under the knives than the knives on the table. This is a natural result of basic facts about tables and knives in the world: tables are more stable, less prone to movement, and less manipulable than knives are. This is, of course, relative.