¿The rain in Spain falls mainly on the plane?

Question

Why this saying? Do you know this origin?

Do you agree on it?

Answer 1

Its origin is Frederick Lerner, who needed a phrase with lots of long a's to demonstrate that Liza Doolittle had learned to make this sound!

Nothing more complicated than that.  

(actually, it might go back a little farther to G. Bernard Shaw, in the non-musical version.  I don´t know that one as well.)

And, no.  It isn't true.  In fact, the plain or La Mancha tends to be rather dry.  The Rain in Spain really falls in the northern Guadarrama mountains and the northern coast.  (known as "green spain").

Answer 2

It's used in elocution lessons it's meant to help us pronounce our words properly. Another one is How now brown cow

Answer 3

It's "plain" not "plane" and has to do with a song from My Fair Lady, stage and movie version!!  Henry Higgins is trying to teach Eliza Doolittle how to speak proper English instead of Cockney.  It means nothing in itself.