Character Analysis
Sven is Minnie's husband (a.k.a. Carrie's brother-in-law), and he's a hard-working, frugal guy:
[Sven] was of a clean, saving disposition, and had already paid a number of monthly installments on two lots far out on the West Side. His ambition was some day to build a house on them. (2.4)
As a pretty no-nonsense dude himself, Sven is utterly baffled by Carrie's desire to spend money on trivial things like going to the theater, making him, along with Minnie, the perfect foil to Carrie:
He was thinking of a full career of vanity and wastefulness which a young girl might indulge in, and wondering how Carrie could contemplate such a course when she had so little, as yet, with which to do. (4.47)