Hostage is a type of Prisoner. Hostage is related to Take. Take is the opposite of Drop. 
you are likely to find Couch in/at/on Doctor. Doctor is a type of Professional. Professional is related to Fee. Fee is related to Penalty. 
Prisoner <--IsA-- Hostage <--RelatedTo--> Take <--Antonym--> Drop 
Couch --AtLocation--> Doctor --IsA--> Professional <--RelatedTo--> Fee <--RelatedTo--> Penalty 