Learn German: Der Computer ist billig, weil das Angebot toll ist. - The computer is cheap because the offer is great.

The word weil (because) introduces a dependent clause. In German, these types of connecting words always kick the conjugated verb to the very end of their clause. So instead of saying weil das Angebot ist toll, we have to say weil das Angebot toll ist.

Do I always need a comma before weil?

Yes! Unlike in English, German grammar requires a comma to separate the main sentence from a dependent clause. Whenever you use weil to add a reason to your sentence, you must put a comma right before it.

What does das Angebot mean in this context?

das Angebot means the offer, deal, or special promotion. You will often see it in stores during a sale, sometimes as Sonderangebot (special offer). It comes from the verb anbieten (to offer).

Can I start the sentence with the weil part instead?

You can! You could say: Weil das Angebot toll ist, ist der Computer billig. Since the whole weil clause acts as the first block of information, the main sentence must immediately follow it with the verb (ist) to keep the main verb in the second position overall.