What is the main conflict in this book?

The main conflict in the story is a class conflict.

“She’s not civilised, at least not enough for me!”

Luo, Page 27

Luo's initial reaction to the Seamstress foreshadows the dynamic of their relationship. After they become romantic, Luo focuses on teaching her things he believes will 'civilize' her. His mission includes reading her Balzac and helping her look and speak more like a city girl. Though his affection with her is undoubtedly genuine, he instinctively patronizes her in his efforts, revealing a certain classist attitude. Even his swimming lessons have a subtext of class conflict – he wants her to use her arms to swim, rather than dog-paddling like the other villagers do. Ultimately, his patronizing purpose backfires when she embodies his lessons so well that she no longer has any use for him.