Breakdown of Würden Sie uns bitte das Salz reichen?
Sie
you (formal)
uns
us
bitte
please
würde
would (conditional auxiliary)
Questions & Answers about Würden Sie uns bitte das Salz reichen?
Why does the sentence start with Würden and put reichen way at the end?
This is the classic structure for making a polite request in German. You use a form of würden (meaning "would") at the start to form the question, and push the main action verb (reichen) to the very end of the sentence in its basic dictionary form (the infinitive).
How would I ask this same question to a good friend?
You would change the formal Sie to the informal du, and adjust the first verb to match: Würdest du uns bitte das Salz reichen?
Why is it uns in this sentence?
The word uns means "us", and here it acts as the indirect object (in the dative case). When you pass something to someone, the person receiving it takes the dative case. The actual thing being passed (das Salz) is the direct object and takes the accusative case.
Could I use geben instead of reichen here?
Absolutely! Würden Sie uns bitte das Salz geben? is perfectly fine and very common. The verb reichen specifically means "to hand" or "to pass" something, which makes it a very natural fit for sitting around a dinner table.