get all of the legendarys on the game, beat the elite four go on to the battle frontier beat all of the trainers on the island and go through every route then go back home to your professer (professer oak) and he or an other prof. will come and upgrade your pokedex to the national dex then to fill it up you HAVE TO TRADE (REMEMBER GBs DON'T TRADE WITH DS in fact i don't know how many there really are just do what i siad because that's the only way i filled up my dex on platinum
Well, if you trade, it should go into your pokedex.
no.
you trade a Pokemon from a friend(not gts place)
Yes.
No, you cannot trade at that point. You can only trade Johto and Kanto Pokemon at that point. No Sinnoh/Hoenn Pokemon are allowed.
Yes.
no but if you don't have the second pokedex you carn't trade any Pokemon so if you only have the first pokedex you can only get the Pokemon from diamond and pearl Pokemon.
get it in a trade
Unfortunately, you have to catch, trade, or somehow own every Pokemon in the pokedex. If you had it at one time and traded it, it still is in your pokedex.
No
You need to trade a Chikorita from Pokemon heartgold or soulsliver
you can't you get 1 when you complete your pokedex not all unless you have another game and you completed the pokedex then save before you get the Pokemon then once you get on you can trade it then do the same with the others.and how r u going to do that? it saves right after u trade hav u ever traded before?