Plot
In London, Professor Henry Higgins, a scholar of phonetics, believes that a person's accent determines their prospects in society ("Why Can't the English?"). At the Covent Garden fruit-and-vegetable market one evening, he listens to Eliza Doolittle, a young flower seller with a strong Cockney accent, and makes notes. This causes others to suspect he is a detective. Eliza protests that she has done nothing wrong and asks Colonel Pickering, himself a phonetics expert, to confirm this. Pickering and Higgins are delighted to become acquainted; in fact, Pickering had come from India just to meet Higgins. Higgins boasts he could teach even someone like Eliza to speak so well he could pass her off as a duchess at an embassy ball. Eliza wants to work in a flower shop, but her accent makes that impossible ("Wouldn't It Be Loverly"). The following morning, Eliza shows up at Higgins's home, seeking lessons. Pickering is intrigued and offers to cover all the attendant expenses if Higgins succeeds. Higgins agrees and describes how women ruin lives ("I'm an Ordinary Man").
Eliza's father, Alfred P. Doolittle, a dustman, learns of his daughter's new residence ("With a Little Bit of Luck"). He shows up at Higgins's house three days later, ostensibly to protect his daughter's virtue, but in reality to extract some money from Higgins, and is bought off with £5. Higgins is impressed by the man's honesty, his natural gift for language, and especially his brazen lack of morals. Higgins recommends Alfred to a wealthy American who is interested in morality.
Eliza endures Higgins's demanding teaching methods and harsh treatment ("Just You Wait"), while the servants feel both annoyed with the noise as well as pity for Higgins ("Servants' Chorus"). She makes no progress, but just as she, Higgins, and Pickering are about to give up, Eliza finally "gets it" ("The Rain in Spain"); she instantly begins to speak with an impeccable upper-class accent, and is overjoyed at Higgins having danced with her ("I Could Have Danced All Night").
As a trial run, Higgins takes her to Ascot Racecourse ("Ascot Gavotte"), where she makes a good impression initially, only to shock everyone by a sudden lapse into vulgar Cockney while cheering on a horse. Higgins is amused. There, she meets Freddy Eynsford-Hill, a young upper-class man who becomes infatuated with her ("On the Street Where You Live").
Higgins then takes Eliza to an embassy ball, where she dances with a foreign prince. Zoltan Karpathy, a Hungarian former pupil of Higgins, watches, listens, dances with Eliza, and finally declares she is a Hungarian princess.
Afterwards, Eliza's hard work is ignored, with all the praise going to Higgins ("You Did It"). This and his callous treatment of her, especially his indifference to her future, causes her to walk out on him, but not before she throws his slippers at him, leaving him mystified by her ingratitude ("Just You Wait [Reprise]"). Outside, Freddy is waiting ("On the Street Where You Live [Reprise]") and greets Eliza, who is irritated by him as all he does is talk ("Show Me"). She tries to return to her old life, but finds that she no longer fits in. She meets her father, who has been left a generous income by the wealthy American to whom Higgins had recommended him and is resigned to marrying Eliza's stepmother. Doolittle feels that Higgins has ruined him, lamenting that he is now bound by "middle-class morality" ("Get Me to the Church On Time"). Eliza eventually visits Higgins's mother, who is outraged at her son's behavior.
The next day, Higgins finds Eliza gone and searches for her ("A Hymn to Him"), eventually finding her at his mother's house. He attempts to talk her into coming back to him. He becomes angered when she announces that she is going to marry Freddy and become Karpathy's assistant ("Without You"). He goes home, predicting that she will come crawling back. However, he comes to the realization that she has become important to him ("I've Grown Accustomed to Her Face"). He turns on his gramophone and listens to her voice. Suddenly, she appears in the doorway. He nonchalantly asks, "Eliza, where the devil are my slippers?" She simply smiles.