The full form of ”訳ない” would be "訳がない,” whereas the full form of ”訳じゃない” is "訳ではない.” This means that the two verbs (in dictionary form) are ”ある” and ”である” (the true version of ”です”), respectively.
So, the first (”訳ない”) is saying that "(there is) no reason," whereas the second (”訳じゃない”) is saying that "(that is) not the reason." So in the case of "there is no reason I should be able to speak Chinese," ”訳じゃない” would make no sense. Only "訳ない” or "訳がない” makes grammatical sense.
Be careful about this one. "ない” and ”じゃない” are seriously completely different verbs in Japanese.
That's not true at all. The
That's not true at all.
The full form of ”訳ない” would be "訳がない,” whereas the full form of ”訳じゃない” is "訳ではない.” This means that the two verbs (in dictionary form) are ”ある” and ”である” (the true version of ”です”), respectively.
So, the first (”訳ない”) is saying that "(there is) no reason," whereas the second (”訳じゃない”) is saying that "(that is) not the reason." So in the case of "there is no reason I should be able to speak Chinese," ”訳じゃない” would make no sense. Only "訳ない” or "訳がない” makes grammatical sense.
Be careful about this one. "ない” and ”じゃない” are seriously completely different verbs in Japanese.