you remember that cave where you save mr.briney's bird? go there, use rock smash, and allow The Karate Kid to go through. He sees his lovely Wanda again, and he rewards you with the one and only HM04, strength.
HM 05 is flash
A HM is a move is a move that can be tought to as many Pokemon as you like but the Pokemon has to be able.
The Pokemon that can learn any move from TM's and HM's is Mew.
You get it after you give the gold teeth that you find in the safari zone to the Old Warren, and he will give you strength.
He isn't in Pokemon Emerald. He is only in pokemon Blue,Red, and Yellow. Sorry.
talk to Wallace
H.M
Zigzagoon and liloone
HM02
9
Tropius and Gyarados together can learn all of the HM's.
you recieve the hm waterfall after you have deafeated the elite 4