So I've noticed that usually is read　にほん But a lot of times in Core 2k They say にっぽん instead, and I've been wondering if there is a reason behind it. Are there situations where you should use にっぽん instead of にほん? And are there actually situations where one of the two would be an incorrect reading?

The most recent sentence I've gotten from Core 2k is 東京は日本の首都です I read that as にほん by habit, but that's not how they said it.

Any explanations would be appreciated.

I think にっぽん is more nationalistic, and maybe more formal. You see a lot of "頑張れにっぽん!" stuff around Olympics time.

EDIT: Daijisen says that although にっぽん is more often used by the government, and in things where Japan represents themselves as a country (sports uniforms, etc) there's no proper rules of when to use them. English Wikipedia says the same thing.

I've had several Japanese people tell me they associate にっぽん with NHK and right-wingers. Probably an over-generalization but most people say にほん, I think.

I agree that some Japanese associate right-wing, nationalistic connotations to にっぽん. What percentage, I don't know.

I've read (from natives) that にっぽん has more sense of national pride to it.

Adding to the confusion, some companies are officially named NIPPON (such as 日本テレビ Nippon Television [1]) while others are officially named NIHON (such as 日本大学 Nihon University [2]).

Bokusenou Wrote:I think にっぽん is more nationalistic, and maybe more formal. You see a lot of "頑張れにっぽん!" stuff around Olympics time.

I think にっぽん is almost always used in the context of sports chants and the like. I think in most contexts there isn't all that much difference, though.

にほん＝Japan
にっぽん＝Our big and powerful nation that is called Japan