"He is coming back in a second."
Translation:Il revient dans une seconde.
Retourner wouldn't make much sense here. In order to use "retourner" the subject must be going back to a place where the speaker isn't or it can mean returning an item. Il vas retourner en France. / He is going to return to France.
He is coming back in a second implies that the person is coming back to the location of the speaker very soon. The best verb for that is revenir.
Retourner, rentrer, and revenir are tricky for English speakers because English doesn't make these types of distinctions. There is just have one verb, "to return". Here is a helpful article: https://www.frenchasyoulikeit.com/retourner-revenir-rentrer-whats-the-difference/
Revenir means to come back to where the speaker is. Rentre means to return "home", whether that is a house or a country.
They are not interchangeable unless the speaker is "home" and "he" is also returning home. The best translation is with revenir. Il revient dans une seconde.
"Rentrer" means "to go/come back (home)", "to return", "to step/go/come in again"... + a place introduced by "à" or "dans", depending on the type of place:
- je rentre à la maison = I go back home
- je rentre dans la maison = (lit.) I enter the house again
This sentence does not mention a place but a "date"
- "in a second (from now)" = dans une seconde (à partir de maintenant)
Another sentence could describe a "duration" with the preposition "en":
- Je rentre en trente minutes means "it takes 30 minutes for me to go/come back (home)".
'dans une minute' -vs.- 'dans une seconde'
Any native speakers perhaps able to help out with this one? Though my French is really bad, I've lived/worked quite a bit in Morocco and Paris, and for some reason 'dans une seconde' seems a bit odd to me.
I am sure I have heard 'dans une minute' being used rather often (in France referring generally to a time span of about 15 minutes, in Morocco of about 60 but that is besides the point ;) ) , but 'dans une seconde' seems less common to me. Are my intuitions right on this?
It is up to the speaker to exaggerate a bit or a lot when giving a time span, which is anyway quite relative.
"Je suis à vous dans une minute" is often said to someone who has to wait until you have finished what you are doing. Some do say "... dans une seconde" in the same situation, knowing that nobody expects that "one second" will be enough, while more often than not "one minute" is not sufficient either.
I thought that doing something DANS a period of time meant that you BEGAN the something at the End of that time. And doing something EN a period of time meant that whenever you started, it would then take that period of time to finish. Hence "Il revient dans une seconde" would mean that he will be starting to come back in one second from now and if it takes him 30 seconds to complete the journey, then "Il revient dans une seconde en trente secondes".