It's been two weeks since i've sprained my ankle the swelling hasn't gone yet how long will it take and what if it's still there i can walk on it?

Water cast.: The swelling has not gone down because the ankle is still unstable. The swelling is the body's way of maintaining stability of the ankle. It is essentially a water cast. Two weeks is apparently not enough time to have any appreciable healing. You will need to use some sort of ankle support for a while. The time is based on the extent of the injury.