Child can be used for Learning. Child is related to Brother. 
Belong is related to Fit. Fit is related to Lose. Lose is the opposite of Acquire. Acquire is etymologically related to Quest. 
Learning <--UsedFor-- Child <--RelatedTo--> Brother 
Belong <--RelatedTo--> Fit <--RelatedTo--> Lose <--Antonym--> Acquire --EtymologicallyRelatedTo--> Quest 