Contribute is a synonym of Bring. Bring is a synonym of Lend. Lend is a type of Be. Be is related to Speech. 
Beg is related to Plead. Plead is a type of Appeal. 
Contribute <--Synonym--> Bring <--Synonym--> Lend --IsA--> Be <--RelatedTo--> Speech 
Beg <--RelatedTo--> Plead --IsA--> Appeal 