Learn German: Sie weint, weil sie das Geld verloren hat. - She is crying because she lost the money.

The word weil (because) is a subordinating conjunction. This means it creates a dependent clause and forces the conjugated verb—in this case, the helper verb hat—to move to the very end of the sentence.

There are two verbs at the end (verloren hat). Why does hat come after verloren?

In a normal main clause, you would say sie hat das Geld verloren (she has lost the money), where the past participle verloren goes to the end. But because weil pushes the conjugated verb (hat) to the absolute end, it lands right after the participle.

Why does the German say Sie weint instead of translating "She is crying" word-for-word?

German doesn't have a separate "is doing" form (the present continuous tense) like English does. A simple present tense verb like weint translates to both "cries" and "is crying", depending on the context.

Do I always need a comma before weil?

Yes! In German, you must always use a comma to separate a main clause (Sie weint) from a subordinate clause (the part starting with weil).