Christopher Booker is a scholar who wrote that every story falls into one of seven basic plot structures: Overcoming the Monster, Rags to Riches, the Quest, Voyage and Return, Comedy, Tragedy, and Rebirth. Shmoop explores which of these structures fits this story like Cinderella’s slipper.
Plot Type : Rags to Riches
Initial wretchedness at home and the 'Call'
Eliza Doolittle has been standing on the corner selling flowers for who knows how long. She's uneducated, dirty, and, to top it all off, has an incredibly thick accent. Oh, and she's also extremely paranoid. Luckily, she has a chance encounter with Henry Higgins, a gifted phonetician and speech teacher. She shows up at his house the day after meeting him and demands lessons.
This is a classic example of the scenario. Eliza is almost literally dressed in rags. She runs into a man who mentions, pretty much out of nowhere, that he could turn her into a duchess, and she has a pretty good idea of how talented a man he is. How could she pass up the opportunity? Well, as we find out, she couldn't. Her journey begins almost immediately thereafter.
Out into the world, initial success
At Higgins's place, Eliza is given a nice bath and fresh clothes. One might say she cleans up well. After a couple months of teaching, she is able to mingle at a party given by Mrs. Higgins, and though her speech and manners aren't perfect, she's got enough going for her to catch the eye of Freddy.
Having already been welcome into a place the likes of which she's never seen (Higgins's apartment), in Act 3 she's brought out into the world in the coming of age, debutante sort of way. She makes her debut on the "at-home" circuit, and though her performance isn't perfect, it certainly qualifies as a success.
The central crisis
A few more months pass, and Eliza is able to "pass" as a duchess. Henry Higgins wins the bet, but he doesn't give any credit to Eliza. She doesn't know what to do with herself, and takes her anger out on Higgins by throwing his slipper at him.
Shaw pulls a little switcheroo here. What we expect to be the triumphant conclusion to the play, Eliza's success as a duchess, turns out to be little more than the beginning of the play's major conflict. When the bet is over, the real drama begins.
Independence and the final ordeal
After her argument, Eliza realizes that she's her own women. She refuses to take Higgins's breakfast order, and leaves to stay at Mrs. Higgins's house later that night. When Higgins shows up there the next day, Eliza is calm, cool, and collected. She can't keep up the act, though, and she is soon arguing with Higgins about his treatment of her, her future marriage prospects, and potential occupations. Eliza threatens to marry Freddy – a prospect Higgins is none too happy about, and, perhaps go into competition with Higgins in the speech training business. Higgins gets angry, nearly strangles Eliza, and proceeds to tell her she's now become his equal.
In the course of their argument, Eliza actually uses the word independent more than once, and though we can't be sure she'll find a way to make it on her own, it's certainly on her mind. And well, the end is truly an ordeal: Eliza nearly gets strangled, after all, but she stands her ground anyway.
Final union, completion, and fulfillment
Eliza says goodbye to Higgins for what she seems to think will be the last time. Higgins thinks otherwise, and tells Eliza to pick up some groceries as she's walking out the door.
This is where it gets tricky. The fifth act concludes, well, inconclusively. The thing is, Shaw wrote a "Sequel to Pygmalion" in which we find out that she does in fact marry Freddy and the two more or less live happily ever after. You can read a more in-depth discussion of the ending in the "What's Up with the Ending?" section, but here's the bottom line: ignore the sequel and make of the ending what you will.