Noreen,You might possible have a better "ear" for languages than I have. When I try to learn lyrics in another language by phonetics, I find that someone who does know the language inevitably comes up after a show and tries to correct me for butchering the song and his or her language.
That's what I mean when I say my singing comes out as "gibberish".
As far as the nonsense translations are concerned, they usually are, in my case, "americanised" enough that I can pronounce them. Many versions (including the version of 'Johnny Has Gone For A Soldier' that I sing) leave out the "nonsense" sections entirely.
Thanks...Mike