Ok...and by "spinning freely" I assume you mean spinning freely in both directions?
Yes. The "clutch dog" in the lower unit that the shift cam and cam follower operate when you shift gears, is locked to the prop shaft via a pin and sits between the gears in N and doesn't touch the teeth of the F or R gear so the prop shaft is free to spin in either direction as much as you wish.
In F gear it locks CCW if attempting to turn by hand and rotates with a click CW. The click is the "overrun clutch" which is not a clutch actually but the F gear and front of the clutch dog teeth are shaped like a saw blade; lock in one direction and slopes that slide over each other in the other. Purpose is when you decelerate, like going from WOT to some lower speed, the engine turns slower than the water running by the prop is turning the prop. This allows both to happen at different speeds. Otherwise when you cut the throttle, the prop would work like brakes on your car and your teeth would wind up in your windshield.
R is square pin and cog and once the pin finds a cog, 3 sets on that engine 120 degrees apart, the pin slips into the cog and the prop is locked in both directions.
