Learn Hardcore Norwegian: Er Deres billett gyldig i dag?

Deres is the formal/polite possessive pronoun meaning your. The capital D signals formal address (like addressing a customer in a very formal letter). Lowercase deres means either your (plural) or their, depending on context. Because of the ambiguity, the capital D is used for formal address.

Is Deres singular or plural?

Formal Deres can address one person or several people. It’s simply “your” in a polite register. Lowercase deres is the regular possessive for dere (you, plural).

Is the whole sentence formal or old-fashioned?

Yes. Er Deres billett gyldig i dag? sounds very formal and somewhat old-fashioned in speech. It might appear in very formal letters, notices, or historical texts. In everyday modern Norwegian, people almost always use du/din or dere/deres.

How would I say this in everyday, natural Norwegian?

Common, neutral alternatives:

To one person: Er billetten din gyldig i dag?
To several people: Er billetten deres gyldig i dag?
Without a possessive (typical from a ticket inspector): Er billetten gyldig i dag?
Very natural alternative with a different verb: Har du gyldig billett i dag?

Why is it billett and not billetten after Deres?

When a possessive comes before the noun, the noun stays indefinite (no -en):

Deres billett (preposed possessive → indefinite noun) If the possessive comes after, the noun is definite:
billetten Deres (postposed possessive → definite noun)

Which position of the possessive is more common: before or after the noun?

Postposed is the neutral, most common choice in modern Bokmål:

Neutral: billetten din / billetten deres / billetten Deres Preposed can feel emphatic or formal:
Emphatic/formal: din billett / deres billett / Deres billett

Why does the sentence start with Er?

Yes–no questions in Norwegian typically put the finite verb first (inversion):

Statement: Billetten er gyldig i dag.
Question: Er billetten gyldig i dag?

How do I negate it: Isn’t your ticket valid today?

Two common options:

Most common: Er ikke billetten din gyldig i dag? (verb + ikke + subject)
Also possible (often more contrastive): Er billetten din ikke gyldig i dag?

Why is i dag two words, and why use i?

The standard spelling is i dag (two words). idag is non-standard in modern Bokmål. The preposition i is used in fixed time expressions like i dag (today), i går (yesterday), i morgen (tomorrow). For days of the week, you typically use på (e.g., på mandag).

Can I use the verb gjelder instead of the adjective gyldig?

Yes. Very natural alternatives:

Gjelder billetten i dag?
Gjelder den i dag? Using gyldig describes the ticket as valid; gjelder asks whether its validity applies today. In practice, both are fine.

Does gyldig change form?

In predicative position (after er), singular stays gyldig, plural is gyldige:

Billetten er gyldig.
Billettene er gyldige. Attributive (before a noun):
en gyldig billett, gyldige billetter, den gyldige billetten.

What gender is billett, and what are its key forms?

Billett is masculine:

Indefinite singular: en billett
Definite singular: billetten
Indefinite plural: billetter
Definite plural: billettene

Where should i dag go in a yes–no question?

The neutral place is at the end:

Er billetten din gyldig i dag? Fronting i dag is fine in statements (I dag er billetten din gyldig), but yes–no questions still begin with the verb.

Is there ambiguity with deres meaning your vs their?

Lowercase deres can mean both your (plural) and their. Context usually resolves it:

Addressing a group: Er billetten deres gyldig i dag? (your)
Talking about a third party: Er billetten deres gyldig i dag? (their) If needed, rephrase to avoid ambiguity (e.g., name the group or owners).

Any quick pronunciation tips?

Er roughly like English “air,” with a tapped/flapped r in many dialects.
Deres like “DEH-res” (two syllables).
billett like “bi-LET” (stress last syllable).
gyldig: the y is a rounded front vowel (like French tu or German ü); roughly “YULL-dig.”
i dag: “ee dahg”; the g in dag may be weak or silent depending on dialect.

How would this look in Nynorsk?

A direct Nynorsk equivalent with a postposed possessive:

Er billetten dykkar gyldig i dag? Formal Nynorsk also has polite Dykk/Dykkar, but this is rare in modern use.