"Él se refiere a nosotros."
Translation:He means us.
OK, I have a book of Spanish idioms and it says that "se refiere a" means "..is concerned .." I think it is one of the impersonal constructions like "se dice" = it is said. So here it looks like the main verb is used reflexively = "He refers himself to us." In that case you must have the 'se' and the "Él" clarifies the subject as "he" Maybe?? :)
I don't see how "He means us" and "He refers to us" are the same. I think of the first as an interpretation, as in he's talking about someone, but he means us. The second makes me think of using us as a reference. Seems like two different things. Again, out of context, it's hard to understand.
I are a iggorant savage but the way I see it: "a nostros" isn't "to us" but "us" with the personal "a". "se" is the reflexive of the object "us". "He to us refers".
The verb is really 'referirse' and it is reflective in Spanish not English. the 'se' means 'himself'. The idiom: ''referirse a' means 'to refers to'. So literally it means 'he himself refers to us'. http://www.merriam-webster.com/spanish/referir The 'a' is not the personal 'a' it goes there even if the object is inanimate.
I chose the third one " He refers to us ". And it was wrong!!!!! Why????? Is Duolingo kidding with us or what ?