Question about Na Adjectives conjugation

5 comments

1. 元気じゃなかったですis a bit more casual

   元気じゃありませんでした。is the more formal way to say it.

   I’m sure someone else will explain it better but that’s how I understand it.

2. It’s the difference between ではありません and ではなかったです, aka formality. You can also turn では to じゃ to sound slightly more casual.

   This applies whenever you conjugate です to the negative past and is in no way unique to な adjectives.

3. They’re both valid negative past conjugations. However, in most situations you find yourself in where 丁寧語 is expected, you’ll be using and hearing じゃなかったです much much more than じゃありませんでした. That’s not to say you can’t use the latter, but you may run the risk of coming across as oddly stiff if you do.

4. As others have said, they’re both valid and are swapping which part of the sentence to conjugate into the past tense and which to formalize.

   Technically it’s considered more correct to say ありませんでした than ないです, but it mostly only matters in written and very formal Japanese. ないです gives off a friendlier, slightly more casual vibe and it’s quite common in everyday speech.

   So 元気じゃなかったです is a little more casual, and it’s also a simpler reply providing a yes/no answer to whether or not the person had been well.

   元気じゃありませんでした is a little more weighty and closer to the most formal response which is 元気ではありませんでした, but it’s still breaking down the formality slightly by turning では into じゃ. It brings a little more attention to the fact that you were unwell, because literally it’s implying “I was some things, but being well was not one of them.”
   Because of that added focus, it might be used as part of an explanation of why you were absent from a recent event, for example.

5. It’s only a difference in formality. ありません is the formal negative form of ある. The informal negative is ない.

   In your examples, you are using the past tense of these, ありませんでした and なかった.