Echo is a type of Single. Echo is a synonym of Ghost. Ghost can cause/lead to Fear. 
Shoe is related to Wear. Hat is a type of Wear. you are likely to find Hat in/at/on Closet. 
Single <--IsA-- Echo <--Synonym--> Ghost --Causes--> Fear 
Shoe <--RelatedTo--> Wear <--IsA-- Hat --AtLocation--> Closet 