All of those who already watched Naruto in Japanese, either the anime or the movies, already know that the orange ninja can’t help ending his lines by "ttebayo" or "dattebayo."
Before translating and explaining this speech mannerism, it is necessary to introduce the concept of yakuwarigo (役割語), or "role language." The yakuwarigo is typical of Japanese language, it allows to handle several levels of politeness, and generally reflects the speakers’ social status and age. All of these notions are encompassed in the keigo concept.
It is quite hard, and sometimes almost impossible to translate examples of yakuwarigo in other languages, as most of them do not have Japanese language’s detailed variety between levels of speech. When asking the same question to a housewife, a company’s director, a little boy or an old lady, you will never hear the same words even though their answers' content will be the same, as all those people necessarily use different grammar and particles. However, such distinctive features can hardly be translated and most of the time they are not, as it happens for anime for example.
There is a necessary loss in translation, be it in the preciseness of the dialogs or in the interpersonal relationships of the characters. This is why it is strongly recommended to watch Japanese anime or animated movies in their original language when possible, as many essential information cannot be translated.
Let’s go back to Naruto, and especially the character’s "ttebayo" / ってばよ. This speech mannerism is composed of:
- って / "tte" a unformal declination of と / "to", a particle used to quote / emphasize the preceding proposition;
- ば / "ba" is the contracted form of 言えば / "ieba", the conditional form of the verb “to say”;
- よ / "yo" is an end of the phrase particle, used to emphasize the speaker’s point of view (sometimes quite intrusively);
- As for だ / "da", it is the neutral form of auxiliary です / "desu" ("to be"), that is sometimes used to link the locution and the yakuwarigo.
It is in fact almost impossible to find a straightforward translation of "ttebayo" / ってばよ, as it is a very specific idiom, that was essentially created for Naruto’s character. If it were to be translated, it may sound as "but since I say that…" As a matter of fact, it shows Naruto’s ego-centric, childish and slightly aggressive personality.
That’s it for the linguistic aspects. But Naruto’s "dattebayo," is more than that, its his personality, a strong distinctive feature, and a punch line. If you listen closely, you will find that many anime or manga characters use such distinctive role language. This feature for characterizing personae is widely used by manga artists, and especially by One Piece’s author Eiichiro Oda.
Have fun spotting the yakuwarigo!