From NHK Easy Japanese News:


If I translate literally:

"About democracy, if stop exercising once, becomes frail like unused muscle therefore, if don't continue exercising don't become," she said.

The last part, logically, seems to be backwards. I would expect either of



Is the original sentence correct and so what is its meaning and why?

I am familiar with "must do" expressions using two potential negative forms like:


But here the ending verb is simply なりません, not a potential form. Would this also express "must do"?

  • 1
    From a purely logical perspective, ~なければなります and ~ればなりません may look like sound forms meaning "must not do ~" (working backward from ~なければならない (= "mustn't not do ~")), but they are highly unidiomatic. Use ~てはなりません/てはいけません for the negative directive. Likewise avoid ~なければなれません. (Use ~なければなりません or ~なければいけません for "must do")
    – goldbrick
    Commented Nov 6, 2016 at 17:43
  • 1
    Possible duplicate of Must do : ~なければならない vs ~なくてはいけない
    – chocolate
    Commented Nov 6, 2016 at 23:54

1 Answer 1


Yes, ~なければなりません also means the same as ~なければいけません. These two can be regarded as fixed phrases.

Therefore 運動を続けなければなりません means "they must continue the campaign."

It's enough if you understand this as a fixed phrase, but this can also be explained in a literal way:

The verb なる can mean "to succeed" or "to complete" as described in jisho.org and ~なければ means "if one doesn't ~".

So ~なければなりません can be interpreted as "if one doesn't ~, it's not ok".

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