Re: 夥 vs. 伙

My impression on 夥 and 伙 is- 

夥 should mostly used as a verb 
夥同，( partner with / group with)
夥同數名黑漢尋仇 ( banded with a few suspected gang members and seek revenge together.)

夥脅 ( taking hostage with threat of force )
夥脅受害人上車 ( force the victim onto a car)

伙 is  mostly a noun or an adjective
大伙兒上! ( everyone go!) 
伙伴 ( companion)
同伙 ( group mate / of the same unit)