Quote 4
LIZA [looking fiercely round at him] I wouldn't marry YOU if you asked me; and you're nearer my age than what he is.
HIGGINS [gently] Than he is: not "than what he is."
LIZA [losing her temper and rising] I'll talk as I like. You're not my teacher now. (5.232-34)
By using incorrect English, by rebelling against the standards of English grammar, Eliza is able to rebel against Higgins as well.
Quote 5
LIZA [pulling herself together in desperation] What am I fit for? What have you left me fit for? Where am I to go? What am I to do? What's to become of me? (4.60)
Having achieved her goal and won the bet, Eliza finds that her metamorphosis has left her confused. Having just "become" something new, she is already afraid of what will come next.
Quote 6
Eliza enters, sunny, self-possessed, and giving a staggeringly convincing exhibition of ease of manner. She carries a little work-basket, and is very much at home. Pickering is too much taken aback to rise.
LIZA. How do you do, Professor Higgins? Are you quite well?
HIGGINS [choking] Am I— [He can say no more]. (5.115-117)
Here, once again, Higgins is stunned to find that his "creation" is now able to control and change her manner with ease. That said, Shaw's use of the word "exhibition" casts the truth of that change in doubt.