I have come across the phrase 気をつけなければ but I do not understand how it works. Google translate says that it means "I have to be careful" but I can't find which conjugation it is using. To me it looks like the provisional form but I don't understand how that fits here. The full sentence is 両親を起こさないように気をつけなければならなかった.


2 Answers 2


V-nak-ereba is an abbreviation of V-nak-ereba naranai. The literal analysis of this is "if (-ba) I don't (-nai) [verb], it won't do (naranai)":

  • 気をつける be careful.
  • 気をつけない not be careful.
  • 気をつけなければ… if they're not careful… (it won't do).
  • 気をつけなければならない if they're not careful, it won't do (=they have to be careful).

Though that's the literal construction, the full expression is just the common, everyday way of saying "I have to [verb]", which is the idiomatic translation. Native speakers don't usually analyze its parts, just like English speakers don't usually think of breakfast as the interruption of fasting, etc.

  • Could you please address the use of ならなかった rather than ならない? I was under the impression that ~ば could not be used for completed conditionals and am having a difficult time comprehending how such a sentence could be taking place in the past. Thanks!
    – G-Cam
    Jul 17, 2017 at 14:08
  • @G-Cam You can have ば with た、 no problem. E.g. just got this from twitter: 「初日買っとけばよかった💦 」 ("if I had bought it on the opening day, it would be good" → the idiom for "I should have bought it on opening day"). In he case of なければならなかった、 again, this is an established idiom for "have to", so it's best to just think of the full thing as: "I had to pay attention" (the literal etymology is: at that point, if I didn't pay attention it wouldn't do). Jul 17, 2017 at 14:16
  • How would I say the negative version, as in "I have to not be careful"? Would "I have to not do" be すればならない or do they not use it like that? Jul 19, 2017 at 9:06

しなければならない is one phrase. It means "must","have to". This ば don't have the meaning of supposition. You don't need to separate into 気をつけなければ and ならない.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .