Negative present endings translated as past tense


I've seen certain translations where I feels like there's a shift in the
tenses.

Ex: なぜ早く言わない!？ translated to "Why didn't you say so sooner!?"

In fact, I've experienced a lot of cases where a character says the word in
it's negative present form in Japanese. For example, imagine a scene where a
sibling fails to wake up the other for some big event. In this case, the other
sibling would say "Why didn't you wake me up"(past) instead of "Why don't you
wake me up"(nonpast). However, what I see instead in Japanese is 起きてくれない
instead of 起きてくれなかった.

Any explanation on the system here would be appreciated.




> **A** :「実は3日前から足を怪我していて……」  
>  **B1** :「なぜ(それを)早く言わない！？」  
>  **B2** :「なぜ(それを)早く言わなかった！？」

Here, Sentences B1 and B2 are basically the same. Both refer to the statement
A just said, and can be translated as "Why didn't you say it sooner?" or "You
should've said that earlier!" The only difference I can feel is that B1 is
slightly more emotional and/or emphatic than B2. In particular, B1 does not
imply A is a person who regularly fails to say important things promptly.

I think B1 is probably an example of [_historical
present_](http://www.englishcafe.jp/englishcollege/etense2/e1-2-1.html), an
employment of present tense to express past things vividly. Despite its
grandiose name, it happens in daily conversations, both in Japanese and
English. But some sources say the Japanese language uses this more often than
English. Tense in Japanese is somewhat more loose than that of English, and is
affected by the speaker's mood.

From my experience, an emotional complaint like this is often the target of
temporary shift in tense. For example, you can say なんでそんなこと言うのかなぁ ("I wonder
why he said such a thing") complaining about what was said yesterday. This
does not mean he is a person who always says odd things.

Some articles which may be related:

  * [historical present, specifically in japanese](http://linguaphiles.livejournal.com/4925137.html)
  * [Tense and Aspect in Modern Colloquial Japanese](https://books.google.co.jp/books?id=9LqLwiAi1aYC&lpg=PA46&ots=zHXs1aba5P&dq=historical%20present%20japanese&hl=ja&pg=PA46#v=onepage&q=historical%20present%20japanese&f=false)

