95736
While both mean "I have to / I must (do sth)", I wonder if there is a slight
difference in the meaning or politeness level or anything else?

For example, do all these pairs sound exactly the same?

  * 時計を直さなくてはいけない vs 時計を直さないといけない
  * もう帰らなくてはいけない時間だ vs もう帰らないといけない時間だ
  * この部屋は掃除しなくてはいけない vs この部屋は掃除しないといけない

Incidentally, it seems that before ならない, ないと is grammatically wrong; only なくては
(or other forms such as なければ) are allowed. Not sure if there's any intuitive
explanation for that.
CC BY-SA 4.0
2022-08-07T16:38:34.743
95729
2022-08-08T01:47:23.620
10268
question
usage
Difference between ないといけない and なくてはいけない
There is no difference in meaning, but in casual conversations, しないといけない is
much more common (perhaps simply because it's shorter). しなくてはいけない would sound
pompous if used in real informal conversations between friends or family
members. しなくては is natural if the speaker is an
[ojōsama](https://www.japanesewithanime.com/2018/05/ojousama.html) or a
stereotypical gentlemen in manga/anime.

しなくては is preferred in business settings, and it's often combined with なりません (a
politer version of いけません).

  * 時計を直さなくてはなりません。
  * もう帰らなくてはならない時間です。
CC BY-SA 4.0
2022-08-08T01:47:23.620
95736
2022-08-08T01:47:23.620
5010
95729
answer