you have to beat the game to trade for Pokemon outside the game but if you've already beat the game just go to the top floor of the pokecenter
just like you do in diamond/pearl. go to the union room on the 2nd floor of the Pokemon center, talk with who you want to trade with, and select "trade"
you trade at a Pokemon center upstairs in the union room. you try to talk to your friend/opponet etc and in the options you choose trade.
Go to a Union Room with a friend
No you cannot trade from Sapphire to Platinum. The closest thing that you can do to that is migrate from Sapphire to Platinum.
It is possible to trade Pokemon platinum to diamond and pearl, but you cannot trade to any other game.
yes. you can trade Pokemon from diamond, pearl, or platinum to heartgold or soulsilver.
You cannot trade, but you can use the relocator with two ds's and transfer Pokemon from platinum to white
you can transfer Pokemon from Pokemon platinum to black and white but you can't trade from black to platinum
you can not get it from Pokemon platinum you can trade in to diamond or pearl
no you cannot't trade Pokemon from Pokemon black to Pokemon platinum or any past games.
Of course
you can trade Pokemon from heartgold and soulsilver to your diamond,pearl, or platinum.
IT isn't in Platinum you have to trade for it from Global trade or Diamond
you trade eggs.
u cant trade. migrate