YOU SAID:

If exactly one person entered now, the house would be empty again.

INTO JAPANESE

今一人だけ入っていたら、家はまた空っぽになっていただろう。

BACK INTO ENGLISH

If only one had entered now, the house would have been empty again.

INTO JAPANESE

もし今一人だけ入っていたら、その家はまた空っぽになっていただろう。

BACK INTO ENGLISH

If only one had entered now, the house would have been empty again.