Learn Hardcore German: Entschuldigen Sie, könnten Sie mir sagen, ob meine Reservierung noch gilt? - Excuse me, could you tell me whether my reservation is still valid?

Sie (capital S) is the formal “you” in German, used for strangers, customers/staff, older people, or in professional settings. It’s always capitalized to distinguish it from sie (“she/they”).
So this sentence is polite/formal: you’re addressing someone like a receptionist, waiter, or clerk.

Why does the sentence start with Entschuldigen Sie? Is that the same as Entschuldigung?

Both are ways to say “Excuse me,” but they’re used a bit differently:

Entschuldigen Sie, … = literally “Excuse me (formal), …” + it directly addresses the person and smoothly introduces a request.
Entschuldigung! = “Sorry!/Excuse me!” often used more like an interjection (to get attention, apologize briefly, bump into someone, etc.).
In this sentence, Entschuldigen Sie, könnten Sie … is a very common polite request pattern.

What does könnten Sie mean, and why not just können Sie?

könnten Sie is Konjunktiv II (subjunctive II) of können and is used to sound more polite/less direct, like English “could you” vs “can you.”

Können Sie mir sagen …? = “Can you tell me …?” (polite, but more direct)
Könnten Sie mir sagen …? = “Could you tell me …?” (more polite)

Why are there so many commas in this sentence?

German uses commas quite consistently to mark clause boundaries:

Entschuldigen Sie, comma after the introductory phrase.
könnten Sie mir sagen, comma before the subordinate clause introduced by ob.
ob meine Reservierung noch gilt? is the embedded yes/no clause.
So the commas help show the structure: main clause + subordinate clause.

Why is the word order könnten Sie mir sagen (verb first), not Sie könnten?

Because this is a question. In German yes/no and many polite-question forms, the conjugated verb comes first:

Könnten Sie mir sagen …? = “Could you tell me …?” In a statement, you’d get:
Sie könnten mir sagen, ob … (less common as a standalone, but grammatically fine)

Why does the verb go to the end in ob meine Reservierung noch gilt?

Because ob introduces a subordinate clause. In German subordinate clauses, the conjugated verb typically goes to the end:

ob
- subject + other elements + gilt
  So: ob meine Reservierung noch gilt (…whether my reservation is still valid)

What exactly is ob here, and how is it different from wenn?

ob means “whether/if” in the sense of a yes/no question embedded inside a larger sentence:

“Could you tell me whether my reservation is still valid?” wenn usually means “if/when” for conditions or repeated events:
Wenn ich Zeit habe, … = “If/When I have time, …”
So for “whether it is valid (yes/no)”, you need ob, not wenn.

What does noch add? Could I leave it out?

noch here means “still”: you’re asking if the reservation continues to be valid up to now.

With noch: “whether my reservation is still valid”
Without noch: “whether my reservation is valid” (more general, less time-focused)
In this context, noch is very natural because reservations can expire or be canceled.

What is gilt? Why not ist gültig?

gilt is the 3rd person singular of gelten = “to be valid / to apply.”

ob meine Reservierung noch gilt = “whether my reservation is still valid” You can also say:
ob meine Reservierung noch gültig ist
Both work, but gilt is very idiomatic and concise.

Why is it mir sagen and not mich sagen?

Because sagen takes:

an accusative for the thing being said (the content), and
a dative for the person it’s said to.
So:
jemandem (Dat.) etwas (Akk.) sagen = “to tell someone something”
Here, mir is dative = “to me.” mich would be accusative and is not used with sagen in this structure.

How would I say this more casually (informal du)?

To someone you address with du (a friend, peer, informal setting), you’d change the verb endings and pronouns:

Entschuldige, könntest du mir sagen, ob meine Reservierung noch gilt?
Or slightly shorter:
Kannst du mir sagen, ob meine Reservierung noch gilt?