Native is a type of Person. Native is related to American. American is related to English. 
Killer is a type of Difficulty. Situation is a type of Difficulty. Poverty is a type of Situation. Poverty is related to Poor. 
Person <--IsA-- Native <--RelatedTo--> American <--RelatedTo--> English 
Killer --IsA--> Difficulty <--IsA-- Situation <--IsA-- Poverty <--RelatedTo--> Poor 