Quote 1
[To Freddy, who is in convulsions of suppressed laughter] Here! what are you sniggering at?
FREDDY. The new small talk. You do it so awfully well.
LIZA. If I was doing it proper, what was you laughing at? [To Higgins] Have I said anything I oughtn't? (3.122)
Here, Shaw demonstrates how easily language can be misinterpreted. What would seem like normal speech on the corner of Tottenham Court Road becomes novel and humorous in a new context.
Quote 2
LIZA. I can't. I could have done it once; but now I can't go back to it. Last night, when I was wandering about, a girl spoke to me; and I tried to get back into the old way with her; but it was no use. You told me, you know, that when a child is brought to a foreign country, it picks up the language in a few weeks, and forgets its own. Well, I am a child in your country. I have forgotten my own language, and can speak nothing but yours. That's the real break-off with the corner of Tottenham Court Road. Leaving Wimpole Street finishes it. (5.152)
Throughout Pygmalion, "correct" language is portrayed as a unifying force. Here, Eliza demonstrates that it can also be divisive.
Quote 3
PICKERING. He's incorrigible, Eliza. You won't relapse, will you?
LIZA. No: Not now. Never again. I have learnt my lesson. I don't believe I could utter one of the old sounds if I tried. [Doolittle touches her on her left shoulder. She drops her work, losing her self-possession utterly at the spectacle of her father's splendor] A—a—a—a—a—ah—ow—ooh! (5.156-57)
Although she has been taught to speak properly, Eliza's "old ways" seem to linger on some deeper level, associated with emotion rather than intellect.