What is the purpose of writing Bernard Shaw play "Pygmalion"?

Shaw was
very interested in language and in how accents and vocabulary stigmatize people and separate
classes. One of the things he wanted to show in his play was that a person could rise in social
class just by changing his or her speech. This was comically illustrated in the movie
adaptation, My Fair Lady, when Eliza finally learned to say "The rain
in Spain falls mainly in the plain," rather than "The rine in Spine falls minely in
the pline." Shaw was also an ardent socialist and wanted to end the caste system that
prevailed in Britain.