Why can't i use HM Strength even though i've taught it to a pokemon? (pearl)

Question

Im trying to get to snowpoint city and have taught strength to a pokemon but it wont let me use strength it just says 'maybe a pokemons move can move the boulder' i have 5 badges

Answer 1

U NEED 6 BADGES! lol, good luck! U NEED THE MINE BADGE FROM BYRON IN CANALAVE CITY!

Answer 2

thats just most likely a glitch if you have all badges needed and have taught the move its a glitch.

Answer 3

you need six badges to use strengh  .

the six badge is in canlave city.

good luck getting your six badge .

Answer 4

you need to get the 6th badge