Act 4 is the most dramatic in the play Pygmalion. It illustrates the success of professor Higgins in transforming Eliza as well as his failure in...

Act IV has the
crisis of Shaw's play, for it is the moment when the conflict presented in the first act comes
to a head.  In this act, the cirisis is the outgrowth of a conflict between Higgins and Eliza. 
After all the efforts that Higgins has made to have Eliza appear to be a lady, he yet perceives
her as a "guttersnipe"; however, Eliza feels that she has undergone a change that
leads to her identity crisis.