"He promises to sell cheese."
Translation:Hij belooft om kaas te verkopen.
How can you tell the difference if "om" is going to be before or after the object?
In this case, "kaas" (cheese) is the object of "verkopen" (to sell), so in a way it is part of the subclause that starts with the conjunction "om".
I am dutch and did this test just for fun, and to see if I could find mistakes.. But I would say: hij belooft kaas te verkopen and not hij belooft om kaas te verkopen.. or both... strange!