Learn Dutch: Aangenomen dat het kapitaal beschikbaar is, starten we morgen. - Assuming that the capital is available, we start tomorrow.

It means "assuming that" and acts as a subordinating conjunction. This means it introduces a dependent clause, which pushes the conjugated verb is to the very end of that clause (... beschikbaar is).

Why does the second half of the sentence use the inverted word order starten we?

This is a classic example of the verb-second (V2) rule. Because the entire first clause (Aangenomen dat het kapitaal beschikbaar is) acts as the first block of information in the main sentence, the main verb (starten) must take the second position right after the comma, flipping places with the subject (we).

Could I use stel dat instead of aangenomen dat here?

Yes, but it changes the nuance. Aangenomen dat ("assuming that") is often used for realistic, practical conditions, making it perfect for business or planning contexts like this. Stel dat ("suppose that" or "imagine if") feels much more hypothetical.

Why use the present tense starten for an action happening tomorrow?

Dutch frequently uses the simple present tense to talk about the future, as long as the sentence contains a clear time indicator. Here, the word morgen makes it obvious that the action is in the future, so the future auxiliary verb zullen isn't needed.