How long will it take them to get to the swimming pool?
How long have you been swimming here?
How long did it take you to reach the top of the mountain?
How long have you been here?
How long have you been waiting for her?
How long has it been raining?
How long does it take you to prepare your homework?
How long will it take me to learn to drive?
How long does it take you to walk to the station?
How long have you been reading this book?