Tongue is related to Language. Persian is a type of Language. 
Mechanic is etymologically related to Machine. Machine is related to Object. Wall is a type of Object. you are likely to find Connection in/at/on Wall. 
Tongue <--RelatedTo--> Language <--IsA-- Persian 
Mechanic --EtymologicallyRelatedTo--> Machine <--RelatedTo--> Object <--IsA-- Wall <--AtLocation-- Connection 