Difference between "なければなりません", "なくてはいけません" and "が必要です”？

F

forgottenmems

Perfume Love

15 Nov 2011

12

0

• 7 Feb 2012

• #1

I know there must be a difference between "なければなりません", "なくてはいけません" and "が必要です" but I don't know what it is. I was under the assumption that they meant, "I need to [blank]" or "I have to [blank]" but I'm not really sure in what contexts you use them. Can they be used interchangeably with any verb/noun + koto?/or even just a noun in some cases (ga hitsuyou desu)? If anyone knows, I'd appreciate a response. Thank you

 

Half-n-Half

先輩

17 Jul 2007

920

70

• 7 Feb 2012

• #2

As far as I understand it, in general,
～ないとだめ/いけない/ならない
～なければだめ/いけない/ならない
～なくてはだめ/いけない/ならない

are, for all intents and purposes, the same. It's just a matter of preference and you'll be understood no matter which you use. You can also shorten it to なくちゃ(だめ/いけない/ならない) or なきゃ depending on how familiar you are with the person you are speaking with. I even remember one of my Japanese lab mates telling me that sometimes he might say something like 行かなきゃいけません to a professor or a 目上, but I think you better ask Toritoribe to be sure on that.

Also, が必要です sounds more formal to me.

 

Toritoribe

松葉解禁

Moderator

Fifteen-year veteran

22 Feb 2008

18,266

4,926

• 8 Feb 2012

• #3

As HnH-san wrote, the difference between ならない and いけない is subtle and they are interchangeable in most cases. The following thread might be somewhat helpful.

Have to | Japan Forum

There is another form for "to need to do"; "casual form of a verb" + 必要がある.

 

F

forgottenmems

Perfume Love

15 Nov 2011

12

0

• 9 Feb 2012

• Thread starter
• #4

Thanks Guys The other thread helped a lot too However, I have one more question. What about "I don't need to [blank]"? I'm lost on how to properly express that sentiment in Japanese. Can you use the same endings (nakereba narimasen etc.) reconfigured or do you have to use different verb endings?

 

Toritoribe

松葉解禁

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Fifteen-year veteran

22 Feb 2008

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• 9 Feb 2012

• #5

"casual form of a verb" + 必要が/はありません
～なくてもいいです

 

Half-n-Half

先輩

17 Jul 2007

920

70

• 10 Feb 2012

• #6

Could you also use "casual form of a verb" + ことはありません ?
For example,
謝ることはないんですよ。

 

F

forgottenmems

Perfume Love

15 Nov 2011

12

0

• 10 Feb 2012

• Thread starter
• #7

Toritoribe said:

"casual form of a verb" + ことはありません ?
For example,
謝ることはないんですよ。

Click to expand...

Got it. Thanks

 

Toritoribe

松葉解禁

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22 Feb 2008

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• 10 Feb 2012

• #8

Half-n-Half said:

Could you also use "casual form of a verb" + ことはありません ?
For example,
謝ることはないんですよ。

Click to expand...

Yeah, that's OK, too.

無理することはない。