Part One

London: The social classes clash at the Covent Garden vegetable market.

Mrs. Eynsford-Hill and her son Freddy are looking for a cab, as is Colonel Pickering. However, the three of them bump into the flower girl Eliza Doolittle, who is just going about her business offering violets for sale. The phonetic professor Henry Higgins observes the scene and takes note of the dialects. He causes confusion when he can tell everyone present exactly where they come from – including Pickering. Higgins invites Pickering to stay with him. Higgins is convinced that language can also change class affiliation. With language lessons, he could even get Eliza a job as a sales clerk.

Eliza begins to dream of a better life.

Eliza's alcoholic father, Alfred Doolittle, tries to get some money from his daughter. Eliza finally gives him a few coins.

Eliza undergoes rigorous language training. At the horse races in Ascot, she has to pass her first test in the presence of Henry's mother, Mrs. Higgins. However, the experiment ends in disaster when Eliza reverts to her old speech patterns. But Freddy Eynsford-Hill is fascinated by Eliza...

Part Two

After further intense language training, Eliza is to be presented to society at a grand ball. The event is a triumph; Higgins has won his bet, and he and Pickering celebrate their success.

For Eliza, however, something more than just her language has changed. She and Higgins have a falling out, and Eliza leaves Higgins.

She meets Freddy, who confesses his feelings to her. Together they walk through Eliza's old neighborhood. They encounter Alfred Doolittle, who is heartbroken. Having unexpectedly come into money through a joke by Higgins, he is supposed to marry and become respectable. Eliza realizes that she cannot return to her old life either.

She looks for Mrs. Higgins and pours her heart out to Henry's mother. Henry finds Eliza with his mother. The two get into another argument. Eliza says goodbye to Higgins for good. She wants to lead her own life – and teach...