In George Bernard Shaw's 1913 play and 1938 film Pygmalion, and in the 1964 musical My Fair Lady as well, beneath the lead plot line of a phonetics professor teaching a pauper to speak English properly lies another course through which they fall in love with each other. However, their falling in love is less obvious in both the play and the film than it is in the musical.
In the play and the film, directed by Anthony Asquith and Leslie Howard, although readers and viewers may suspect Eliza (Wendy Hiller) has feelings for Professor Higgins (Leslie Howard), it is not known for sure until the end of the play when Eliza has a breakdown after winning the bet and Professor Higgins becomes hysterical when he learns that Eliza has left the house, and, is really going to marry Freddy.
In the musical, directed by George Cukor, Eliza (Audrey Hepburn) is obviously in love with Professor Higgins (Rex Harrison) when viewers see her dancing with delight in her bedroom after the "Rain in Spain" breakthrough when Professor Higgins dances with her while caught up in his own excitement. Although, Professor Higgins' feelings are not known until, as in the film, he realizes Eliza has left his house, and, later and more obviously, when he sings about how "accustomed" he had grown "to her face."
Knowing Eliza's feelings toward Professor Higgins earlier in the musical provides an additional understanding to her leaving the home when he refuses to say how much she meant to him and how she had helped him win the bet through her own talents, not necessarily those he taught her.
Through this early notification of love, viewers gain an insight to Eliza that is not as readily available in the film and play. Sometimes people-not just Professor Higgins-need a little help to realize exactly what is going on right in front of their faces.