Communication breakdown

What exactly is the breakdown in communication described in the lyrics of Communication Breakdown? Plant seems to be expressing himself with no problem. Does his girlfriend not speak English?

My friend Bob brings up an excellent and timely point. Though personally I’ve always wondered if Led Zeppelin’s English fans understood the Aw Shucks just before the guitar solo, or if that was on the American release only. They don’t say Aw Shucks in England or in any of the dominions or even Ireland, not now and not in 1969. Indeed, on the much rarer English version single, Robert Plant says We Will Nevah Surrender while in a dress, on the even rarer Irish 78 he screams Faith and Begorrah as Bonham does a clog dance on the drums, and on the strictly imaginary Australian 8-track Plant and a herd of freshly sheared sheep bleat Tie Me Kangaroo Down as Jimmy Page plays a classical part on the 12 string. They had to, as Aw Shucks was completely indecipherable to them.

OK, maybe I haven’t always wondered that.