Learn Dutch: We zijn aan het koken, want we hebben honger. - We are cooking, because we are hungry.

It doesn't change it at all! Want (because) is a coordinating conjunction. This means it just glues two normal sentences together. The second part, we hebben honger, keeps the standard Subject-Verb-Object word order, just like a standalone sentence.

Why does the sentence use hebben honger instead of "zijn honger"?

In Dutch, you don't say "we are hungry." Instead, the literal translation is "we have hunger." Because of this, you must use the verb hebben (to have) rather than zijn (to be) when talking about being hungry.

What does aan het do in the first part of the sentence?

It shows that an action is ongoing right now, just like the "-ing" ending in English. The Dutch structure is zijn (to be) + aan het + an infinitive verb like koken (to cook). So, We zijn aan het koken translates to "We are cooking".

Do I always need a comma before want?

Yes, a comma is normally required before want. In Dutch, you typically place a comma before conjunctions that connect two complete sentences, such as want (because) and maar (but).