~たform　／　~辞書form　+　場合は


In「みんなの日本語」, the first part of this sentence, with the た-form verb, is
translate in simple present tense :

> 時間に **遅れた** 場合は、会場に入れません。  
>  If you are late, you will not be able to enter in the room.  
>  _Si vous êtes en retard, vous ne serez pas autorisé à entrer dans la
> salle._

It's translate in french, maybe there is french here... I translate the
sentence in english, sorry if it's not correct.

So, if the translate is good, with「場合」, why use the た-form (past) instead of
the 辞書-form (普通形present) for present tence?

With た-form, it should be :

> If you were late, You couldn't have entered in the room.  
>  _Au cas où vous étiez / auriez été en retard, vous n'auriez pas pu entrer
> dans la salle._

No ? Or, did I missed something?

Thanks




As a non-native English speaker myself, I advise you not to try to understand
the English translation, specially if English is not your native language. I
think it's more useful to just understand the situation in which you can use
each expression, so you don't need to rely on other languages to understand
those expressions.

Let's imagine you are appointed at 5pm and that you should be in that room by
5pm, and let's compare each case.

> 遅れた場合は

I think that saying 遅れた場合は, it is conveyed that you _actually arrived to the
room_ , but you did it at a later time than it should be (in our example, this
means the case where you arrived at the room but it's already 5:15, for
instance). So it would be "in the case you had arrived late to the room".

> 遅れている場合は

If you said 遅れている場合は, it would be "in the case you are running late", so in
this scenario you would be travelling from somewhere to the room, and late on
time, but you would still have a chance to catch up and arrive on time by
running. In our example, you are in the other side of the city and you are on
your way to the room. However, it's already 4:45, so it is very unlikely that
you will arrive in time. But you are not in the room yet, and it's not 5:00pm
yet.

> 遅れる場合は

If you say 遅れる場合は, it sounds like "in the case you are to be late", or "in the
case you will arrive late".

My English translations are probably wrong grammarwise, but I hope you got the
point.

* * *

It might help you to understand it if you think of the expression Verbた + 時
and Verb-辞書形 + 時, where a similar thing happens:

> 家に帰った時、「ただいま」と言います。"We say "tadaima" when we have come back home". You are
> already at home.

> 家に帰る時、「お疲れ様です」と言います。"We say "otsukaresamadesu" when we go back home". You
> are not at home yet. You are about to go back, but you are still in the
> workplace.

