"I will not be free tomorrow."
Translation:Je ne serai pas disponible demain.
"Disponible" is a new word for me. When I could not find "libre" for "free," I clicked on "free" & "disponible" was not even given as an option.
FYI. It's now added as a hint. "Libre" is also a default translation. "Disponible" (available) is not a word taught in the French course, but "available" appears in the reverse course. Hence its appearance in this reverse exercise.
《Je ne serai pas libre demain》accepted by DL.
Disponible means available
If DL means 'available' then disponible is clearly correct - but to use 'free' and translate as disponible presumes a context not given. A prisoner could be speaking for instance. If there is no context either is acceptable in UK English