Não tens dinheiro, porque gastas muito. You have no money because you spend a lot.
Visto que choveu, não precisamos de regar as plantas. Since it rained, we don't need to water the plants.
In all of the examples above, the comma separates the two different parts of each sentence. Note that the dependent clause has no fixed order in the sentence; it can appear either before or after the main clause, as long as it’s properly introduced by the conjunction.