What is Feynman's "fake Italian" as discussed in the book, Surely You’re Joking, Mr. Feynman!?

Although Feynman does not understand Italian, he enjoys listening to the local Italian radio station, due to the rhythm of the language and the emotive quality of the characters on the programs. He begins to mimic the sound of the words, creating his own "fake" Italian. He discovers that if he speaks "Italian" with confidence, people will not realize he does not actually understand the language.