I know JPN. cards are not allowed in the english tournaments, and the same for european cards. But what about official spanish cards printed by ude? Are they allowed in the Tournaments in North America?

1.) Don't say "jap" (considered derogitory)

2.) I'm not sure, but I don't know why they would if they don't allow European cards...

i just checked, and they do allow european english cards. They don't allow asian-english cards.

What should i use instead of "jap?" Should i use jp? I can't spell japaniese correctly.

Just say Japanese...or JPN

Well, ALL cards printed by UDE are legal for use in their tournaments, even if it's Spanish, or French, or anything.

thats sweet. Looks like i will use my spanish thunder giant in my deck than (ultimate rare too).

Sounds fine. If you do that, though, just check with the Tournament Organizer beforehand to make sure that there's an English-print "Elemental Hero Thunder Giant" in the vicinity in case of text disputes.