Lyric discussion by Rockanroll2 

Cover art for Smile Away lyrics by Paul McCartney

I've listened to this song since it was released. But, it wasn't until a few weeks ago I really listened to the chorus behind the main lyrics. I always thought it was just nonsense in harmony sung by Linda, but; "I don't know how to do that. I don't know how to do that..." Then, "I'm learning how to do that. I'm learning how do do that..." It makes sense for the theme of the song, but I'm not sure I'm hearing it correctly.