I was given the sentence
¿Quiénes os están haciendo las camas?
and asked to put it into the form:
using the objeto indirecto (OI) and the objeto directo (OD).
The OD is quite obviously "las camas", so the pronoun would be "las".
But I can't for the life of me work out what the OI is, is it "os" or is it "ellos", i.e is the pronoun "os" or "se"?
Finally, what the resulting sentence be:
Ellos os las están haciendo
Ellos se las están haciendo
This has been bugging me for a while so I'd appreciate any answers!