Use this domain for words that mark the beneficiary of an event. The sentence "John built a house for his father" is ambiguous. If the house was for his father to live in, then "for" would mark the 'Beneficiary of a patient', meaning that the house was for the father. If, on the other hand, the father was intending to build the house to sell, but couldn't due to an injury, then "for" would mark the 'Beneficiary of an event', meaning the father benefited from the building of the house.