Kate as matriarch
Kate's character symbolizes matriarchy. She is the provider for the family and is a teacher by profession. This means she is used to being the authority figure. Kate also has passionate beliefs that underscore the feminine side of authority. She is staunchly traditional, both in religious and cultural ways, and in her relationship to sacrifice and filial piety. To Kate, being Catholic is part of existing as an Irish person. She sees life as a platform for sacrifice, working to sacrifice for the "tribe."
Jack as foil
Christina's seven-year-old son, Michael, turns out to be the narrator. In the context of their family dynamic, this makes his uncle Jack a kind of foil. The comparative aspect of Jack's character is primarily his age and experience. Compared to Michael's innocence and confusion, Jack's own informed point of view is informative. Jack's experience of traditional living (he was a missionary for the church) led him to unique, philosophically open-minded beliefs about religion. Michael can also expect such an awakening in his relationship to family. Jack's experience shows that people who disagree with traditional systems are often treated as scandalous.
The absent father turned warrior
Michael's absent father is a symbolic character, representing Michael's own experience of his masculinity. Michael's father is only around to teach the basics. The portrait of masculinity that Michael receives is essential but dubious: His father first sells gramophones, showing industry, competition and economy as a masculine trait, and then he decides to go to war in a nation he has nothing to do with. Michael's experience of masculinity is that being a man is confusing, lonely, competitive, and sometimes violent.
Money struggles
The family's money struggles are a symbolic reminder that sacrifice is incredibly difficult. The family must pool their resources to make their way through life. The family's money issues only get worse when a factory outmodes the sisters' knitting business. The progress of time is an enemy to family life, to economic stability, and to the family itself. Time and money are both scarce resources in the novel. Eventually, money and time have their full effect on the family; Michael says that everything ends up changing—as it always does!
Crisis and change
Kate's authoritarian and traditional approach to life is shown as essentially good and correct, because the family depends on her and she is able to help them by work and sacrifice—but in a subtle way, her approach to life is also defeated by Jack and Michael's insightful and contrary opinions. Through motif, the novelist explains what kinds of change can emerge from crisis and pressure. The money pressure radically changes the family dynamic, says Michael. The traditional pressure of life as a missionary leads Jack to a wildly different experience of religion. In the end, the motif is clear: By holding onto the traditional ways of the past, one only staves off the effects of change for a time, but in the end, time always catches up, and change comes with or without one's approval. Kate sees this happen before her very eyes.