Ga'-: (marker) Animal classifier, pet.
Note: Chamorro makes use of several different markers/classifiers when constructing possessives, I'll try to get a lesson on this posted.
"Kao ga'-mu ga'lågu enao?" = "Is that your dog?"
"Dumånkolo i ga'-hu babui esta." = "My pig has already gotten big."
"Gof metgot i ga'-ña karabao." = "His water bufalo is very strong."