Når søppelsekken er full, knyter vi den igjen og kjøper mer tørkepapir i butikken.

When the trash bag is full, we tie it up and buy more paper towels in the store.

Breakdown of Når søppelsekken er full, knyter vi den igjen og kjøper mer tørkepapir i butikken.

• være: to be
• vi: we
• butikken: the store
• i: in

Questions & Answers about Når søppelsekken er full, knyter vi den igjen og kjøper mer tørkepapir i butikken.

Why does Når come first, and is it the same as da?

Når introduces a time clause meaning when/whenever something happens (often general or repeated situations): Når søppelsekken er full … = When/whenever the trash bag is full …
Da usually points to a specific time in the past (when/then in a particular situation). So Når is the natural choice for a routine/habit.

---

Why is the verb knyter before vi? Shouldn’t it be vi knyter?

In Norwegian main clauses you get V2 word order: the finite verb is in the second position.
Here the sentence starts with a subordinate clause (Når … full,). After that clause, the main clause begins, and the verb must still be second—so it comes before the subject:

• Når …, knyter vi … (verb 2nd) Not: Når …, vi knyter …

---

Is søppelsekken definite? Why not en søppelsekk?

Yes—søppelsekken = the trash bag (definite). Norwegian often uses the definite form for something specific in the shared context (e.g., the bag we use).
en søppelsekk would mean a trash bag, more like introducing one for the first time or speaking generally.

---