Any difference between the 3 for conditional? Shinai-to can also be just nai-
to for verbs like taberu.

Is the difference that the last 2 only can be used at the start of the
sentence whhile shinai-to can only be used at the end (unless Sou is added to
become "Sou Shina-to")?
CC BY-SA 3.0
2017-12-30T21:23:36.033
55545
2022-01-25T02:05:05.453
2017-12-31T09:04:54.523
22417
22417
question
grammar word-choice nuances sentence
～しないとｖｓでないとvsさもないと
さもないと has a very restricted and loaded usage, and not technically a
conditional. It's only used in situations such as "Otherwise / On failure,
[here come some bad consequences]".

しないと and でないと are respectively...:

  * しないと = `する` ("do") + negative + `と` ("if/once...") "if (something) doesn't do"
  * でないと = `だ／である` (copula) + negative + `と` ("if/once...") "if (something) is not"

But as you said, some phrases starting from a copula are allowed to be used in
the beginning of a sentence as conjunctions, as if the entire previous context
connects to them: だが, だけど, だから, でも etc.

As such, でないと (and its colloquial form じゃないと) can stand at the beginning of a
sentence to mean "if it is not the case" or "otherwise", but しないと just means
what it would.
CC BY-SA 3.0
2018-01-02T11:12:32.677
55613
2018-01-02T11:12:32.677
7810
55545
answer