Breakdown of Du musst den Gastgeber begrüßen. Es ist hier nämlich die Sitte.
sein
to be
du
you (informal singular)
es
it
hier
here
Questions & Answers about Du musst den Gastgeber begrüßen. Es ist hier nämlich die Sitte.
What exactly does nämlich do in this sentence?
It gives the reason or explanation for the statement that came right before it. It acts a lot like saying "you see" or "because" in English. The second sentence explains why you have to greet the host.
Can I put nämlich at the beginning of the second sentence, like "Nämlich es ist hier die Sitte"?
No, nämlich almost never goes at the very beginning of a sentence. It usually sits in the middle of the sentence, after the conjugated verb (ist) and often after short pronouns or adverbs like hier.
Why is it den Gastgeber instead of der Gastgeber?
The host is the direct object receiving the action of the verb begrüßen (to greet). Since Gastgeber is a masculine noun (der Gastgeber), it changes to the accusative case (den Gastgeber) when it is the direct object.
Does die Sitte mean a strict rule or a law?
Not quite. die Sitte translates to "custom," "tradition," or "social convention." It refers to unwritten manners and what is socially expected, rather than a formal rule (die Regel) or a law (das Gesetz).
Just to review, why is at the very end of the first sentence?