If you're having trouble trading it may be for a few reasons
You need to use a GBA or GBAsp and link cable/ wireless adapter. The games are programed to work only with those things. A Nintendo DS doesn't send the game the code it needs to recognize that it has wireless capabilities.
another reason it may not work is that you have not played the games enough to unlock trade between them.
you need the sapphire stone you get on the islands in fire red
No. In order to trade any Pokemon from ruby and sapphire, you need to find and give the ruby and sapphire to celio on first island.
Trade it from pokemon fire red or pokemon leaf green
Trade Trade from Leaf Green or Fire Red you have to trade it from fire red to sapphire to ruby to emerald!
You can do this after you find the Ruby and the Sapphire for Celio in Pokemon FireRed. then you can trade with Ruby, Sapphire and Emerald.
You cannot. Trade it from Fire Red or XD.
trade from fire red or leaf green
You can't catch a poliwag in Pokemon Sapphire. You have to trade from Pokemon Fire Red or Pokemon Leaf Green.
you have to trade for it You can trade from Emerald, Fire Red or Leaf Green
get the ruby and sapphire
YES, YOU DUMMY!(after you defeat the Pokemon League and get the Ruby/Sapphire.)
nowhere, you have to trade for it You can trade from Emerald, Fire Red or Leaf Green