It was a Sunday evening in October, and in common with many other young ladies of her class, Katherine Hilbery was pouring out tea.
-- Narrator (chapter 1 paragraph 1)

Importance: This is the very first sentence of the novel, and it immediately establishes both the setting and Katherine's place within it. The novel begins by placing Katherine in the domestic sphere, doing a domestic task, and asserting that this type of task is common to the class to which she belongs. This opening quote therefore alerts the reader to the fact that Katherine is part of an established social order and subscribes to a particular routine.

The quality of her birth oozed into Katherine's consciousness from a dozen different sources as soon as she was able to perceive anything.
-- Narrator (chapter 3 paragraph 3)

Importance: Here, the narrator explains the extent to which Katherine's renowned family name and high social status actually precede her own personhood. The persistence of the Alardyce legacy...