You can get the HM strength, in the 5 floor of the lost tower. The lost tower is located south of Solaceon Town.
none you have to teach it to a fighting type
lost tower :D
Veilstone Gym.
HM 4
Go to the lost tower
Veilstone.
one of you Pokemon in your party need to learn strength.
in the cave with big boulder
Beat Byron then get strength and then you can use it.
Yes it can learn strength
The HM strength
Tower on route 209.