Higgins in a professor of linguistics and the creator of a universal alphabet. He has spent his life studying dialects. Prior to engaging with Eliza, he has been taking notes in a crowd, recording their geographical background by means of their pronunciation. On a bet, he says he could take Eliza's low class Cockney flower girl and pass her off as a Duchess among the upper classes. The fun of this very fun play is to see the transformation and the big test, in which Eliza, in fact, does convince even the most discerning among the upper classes that she is well-bred.
Shaw wrote plays to satirize his contemporaries, and Pygmalion satirizes prejudice regarding language. In England, class created a seemingly insurmountable economic and social barrier. Even today, people alter their dialect or accent to seem more "posh," and the Upper Received Pronunciation (formally called The King's English) that others associate with "proper English" was a largely invented accent. Shaw was interested in the social, professional, and economic privilege that accrues to those who speak this accent and who are associated with the world they inhabit, such as Eton and Oxford.
People may have believed that England was becoming more egalitarian and that hard work and earnestness would allow people born in to lower classes to improve themselves. Hidden prejudices, however, created obstacles, and pronunciation, says Shaw, is one of the hidden prejudices people hold against those born to lower status.
In the first moments of the play, he comes out as a staunch defender of elevated language and is willing to sneer outwardly at those who speak a lower dialect, whereas others may discriminate based on other associated qualities. Higgins, a man with linguistic superiority, lacks the discrete manners often associated with the English and proclaims for all to hear:
You see this creature with her kerbstone English: the English that will keep her in the gutter to the end of her days. Well, sir, in three months I could pass that girl off as a duchess at an ambassador's garden party. I could even get her a place as lady's maid or shop assistant, which requires better English. That's the sort of thing I do for commercial millionaires. And on the profits of it I do genuine scientific work in phonetics, and a little as a poet on Miltonic lines.
Higgins says that he can do what seemed impossible at the time: to altar a person's social class and move Eliza out of the dire poverty into which she was born. In changing her pronunciation, and therefore how others perceive her class, he can open a world of privilege and opportunity. The poor cannot afford choice or even, as Mr. Doolittle claims, morality but largely because of the caste system subtly governing English society. To change the markers of the caste system, notably pronunciation, is to change one's options.