I have a weak ankle. Are there exercises to help strengthen it?

you can still have a workout with a sprained ankle. Its most important to listen to your body. Its normal to have some discomfort, but when you start to feel pain you should slow down. I play basketball so I've had many sprained ankles. Here is a website with some different ankle strengthening exercises. If you feel youu need some stability then yes you should tape it or wrap it in an ace bandage, but not too tightly.

http://www.shapefit.com/ankle-exercises.html

Goodluck!

I'm not sure about the sprained part, but when it's healed, stand next to something like a kitchen counter and put your hands on the edge, and lift your heels up and down with your toes a couple of times, then alternate by lifting your toes up with your heels. Do the reps a couple times a day. Your ankles will gain strength in the front and back :)

Faith's remedy for the sprained ankle sounds very good.