The thing is, at least in my experience so feel free to disagree, whenever I toss a 'nade while shouting "GREEENAAADE!!!" for whatever reason most of the time any nearby teammates take that as a cue to rush forward right to the exact place it landed. I don't know whether that is because in every language but English "Grenade" means "charge forward", because people just like to spite me by lowering my score, or because most pubbies really are that retarded. But regardless, the shouting serves no purpose but to alert the enemy as to the direction from which said grenade is flying.