A heavy late-night summer thunderstorm opens the play. Caught in the unexpected downpour, passersby from distinct strata of the London streets are forced to seek shelter together under the portico of St Paul's church in Covent Garden. The hapless Son is forced by his demanding sister and mother to go out into the rain to find a taxi even though there is none to be found. In his hurry, he knocks over the basket of a common Flower Girl, who says to him, "Nah then, Freddy: look wh' y' gowin, deah." After Freddy leaves, the mother gives the Flower Girl money to ask how she knew her son's name, only to learn that "Freddy" is a common by-word the Flower Girl would have used to address anyone.
An elderly military Gentleman enters from the rain, and the Flower Girl tries to sell him a flower. He gives her some change, but a bystander tells her to be careful, for it looks like there is a police informer taking copious notes on her activities. This leads to hysterical protestations on her part, that she is only a poor girl who has done no wrong. The refugees from the rain crowd around her and the Note Taker, with considerable hostility towards the latter, whom they believe to be an undercover cop. However, each time someone speaks up, this mysterious man has the amusing ability to determine where the person came from, simply by listening to that person's speech, which turns him into something of a sideshow.
The rain clears, leaving few other people than the Flower Girl, the Note Taker, and the Gentleman. In response to a question from the Gentleman, the Note Taker answers that his talent comes from "simply phonetics...the science of speech." He goes on to brag that he can use phonetics to make a duchess out of the Flower Girl. Through further questioning, the Note Taker and the Gentleman reveal that they are Henry Higgins and Colonel Pickering respectively, both scholars of dialects who have been wanting to visit with each other. They decide to go for a supper, but not until Higgins has been convinced by the Flower Girl to give her some change. He generously throws her a half-crown, some florins, and a half-sovereign. This allows the delighted girl to take a taxi home, the same taxi that Freddy has brought back, only to find that his impatient mother and sister have left without him.
This act is carefully constructed to portray a representative slice of society, in which characters from vastly different strata of society who would normally keep apart are brought together by untoward weather. It is no coincidence that this happens at the end of a show at the theater, drawing our attention to the fact that the ensuing plot will be highly theatrical, that its fantastic quality is gleaned from the illusionary magic of theater. While the transformation of Eliza in the play focuses on speech, each one of her subsequent tests is also something highly theatrical, depending on the visual impact she makes, and how she moves. The highly visual, on top of aural (therefore, altogether theatrical), way in which the flower girl is made into a duchess is emphasized right from this opening act. Under these terms, it should help us to think about the comparison of the artificial makeover of Eliza Doolittle that the phonetics scientist can achieve, to the genuine increase in self-esteem that the considerate gentleman can bestow upon her.
The confusion of the thunderstorm foreshadows the social confusion that will ensue when Higgins decides to play god with the raw material that the unschooled flower girl presents to him. In this act, everyone is introduced in very categorized roles. In this scene, Shaw introduces almost all his major characters, but refers to them by role rather than name in his stage directions: Note-Taker, The Flower Girl, The Daughter, The Gentleman, etc. Furthermore, his stage directions describing where characters stand with every line, particularly in relation to other characters, come across as more than fastidious in their detail. All this evokes a society whose members have rigid relations to one another. The odd, seemingly irrelevant episode when The Mother gives the Flower Girl money to find out how she knew her son's name shows the Mother's fear that her son might be associating with the wrong sort. The incident also conflates a real name with a common term that can apply to anyone; Freddy is for a moment both term and character. By the end of the act, The Note-Taker, The Gentleman, and The Flower Girl have become Higgins, Pickering, and Eliza, respectively. This move will continue through the length of the play, where a less visible blooming of real persons out of mere social positions occurs. If Higgins is one kind of Pygmalion who makes a flower girl a duchess, Shaw is a grander, more total Pygmalion who can will transform mere titles into human names.
Remembering that Pygmalion is subtitled "A Romance in Five Acts," this act strikes us as a rather odd, unceremonious way of introducing the heroes of a romance. For starters, the heroine is described as being "not at all a romantic figure." The hero calls the heroine a "squashed cabbage leaf," while she can do no better than "Ah-ah-ah-ow-ow-ow-oo" back at him. The impression she makes on him is abstract (as an interesting phonetic subject) while that which he makes on her is monetary (he throws her some change), so that we get no indication at all that any feelings of affection will eventually develop between these two. Indeed, we must see the play as a deliberate attempt by Shaw to undo the myth of Pygmalion, and, more importantly, the form of the romance itself. Bearing this in mind, it is possible to approach the rest of the play without a preconceived idea of how a romantic play should conclude, and to notice, as Shaw intends, that there are more utilitarian than romantic aspects to the characters' relationships with one another.