Learn Dutch: Zou u de reservering kunnen bevestigen? - Could you confirm the reservation?

Even though the formal u might feel like a special case, it uses singular verbs in the past tense. For the verb zullen (will), the past tense singular is zou. So it is always zou u, just like zou ik or zou hij.

How does adding zou change the meaning compared to just asking Kunt u de reservering bevestigen?

Asking Kunt u... simply means "Can you...". By combining zou (would) with kunnen (to be able to), you are literally asking "Would you be able to...". This hypothetical phrasing is one of the most common ways to make a request sound extra polite in Dutch.

Why are there two verbs stacked up at the end of this sentence?

Because this is a yes/no question, the conjugated verb zou moves to the front. Dutch grammar rules dictate that any remaining verbs get pushed to the very end of the sentence as infinitives (the full dictionary form). Here, those are kunnen and bevestigen.

Does the order of the two verbs at the end matter? Why is it kunnen bevestigen?