you are likely to find Head in/at/on Helmet. Chair is a type of Head. Chair is related to Useful. Useful is related to Product. 
you are likely to find Bowl in/at/on Sink. Sink is a synonym of Settle. Chair is etymologically related to Settle. Chairman is a type of Chair. 
Helmet <--AtLocation-- Head <--IsA-- Chair <--RelatedTo--> Useful <--RelatedTo--> Product 
Bowl --AtLocation--> Sink <--Synonym--> Settle <--EtymologicallyRelatedTo-- Chair <--IsA-- Chairman 