質問: I encountered a question in my JLPT n1 practice book , and I got really confused because I was sure my answer was right but when I look at the answer sheet the answer is really far from what I have learned so far. the question was ``` その日、私はホームに入ってきた電車に飛び乗った。ところが、電車は反対方向に走り始めた( )。 私は電車の行き先を確かめなかったことを後悔した。 1.ではない 2.ではないか 3.のではない 4.のではないか ``` my answer was 4 but it says on the book its 2. Up until now I know that I have to put の after verb+た or verb +る in order to place ではないか. and the sentence "私はホームに入ってきた電車に飛び乗った。" really confuse me Does it mean " I took the train that just arrived" ? can someone help me with this one?
回答: This `[verb] + ではないか` is an exclamatory phrase which denotes the speaker's surprise or accusation. > > [*]電車は反対方向に走り始めた**ではない**。 (Ungrammatical) > > > 電車は反対方向に走り始めた**ではないか**。 > > **(To my surprise,)** The train started to run in the opposite direction! > > > 電車は反対方向に走り始めた**のではない**。 > > It is not that the train started to run in the opposite direction. > > > 電車は反対方向に走り始めた**のではないか**。 > > **(I wonder,)** Didn't this train start to run in the opposite direction? > > > 4 is incorrect, because the following sentence says 後悔した, which indicates he realized (rather than just wondered) something bad in the second sentence.