Learn Hardcore Norwegian: Omsetningen vokser hver måned.

Omsetningen usually means the turnover, the revenue, or sales, depending on context. In business Norwegian, it often refers to the amount of money a company brings in from sales.

The ending -en makes it definite, so it is the turnover/revenue, not just turnover/revenue in general.

Why is it omsetningen and not omsetning?

Norwegian often adds the definite article to the end of the noun instead of using a separate word like the.

omsetning = turnover / revenue
omsetningen = the turnover / the revenue

So the sentence is talking about a specific turnover/revenue, not the concept in general.

What form is vokser?

Vokser is the present tense of å vokse (to grow).

å vokse = to grow
vokser = grow / is growing

In Norwegian, the present tense is often used where English might say either grows or is growing, depending on context.

Why does not change for ?