Learn Hardcore Norwegian: Dette parfymeriet har den eldste oppskriften på økologisk parfyme i byen. - This perfume shop has the oldest recipe for organic perfume in the city.

Singular: den/det
- superlative + definite noun (e.g., den eldste oppskriften, det beste hotellet)
Plural: de
- superlative + definite noun (e.g., de høyeste bygningene)

Here, oppskrift is common gender, so you use den.

Why eldste and not eldst?

eldste is the attributive superlative form (used before a noun): den eldste oppskriften
eldst is the predicative form (used after a verb): Oppskriften er eldst i byen
Comparative is eldre: en eldre oppskrift

Can I say den eldste oppskrift without the -en?

No. With attributive superlatives you need the definite form of the noun: den eldste oppskriften (or feminine oppskrifta). Saying den eldste oppskrift is ungrammatical.

Why oppskriften på økologisk parfyme and not oppskriften for økologisk parfyme?

The idiomatic preposition is på with oppskrift to mean “recipe for”: oppskrift på kake/suppe/parfyme.

for sounds odd here.
til is used for possession or association: oppskriften til mormor (“Grandma’s recipe”).

Could I use organisk instead of økologisk?

Normally no. In Norwegian, økologisk is the standard word for “organic” (certified/eco-friendly products). organisk usually means “organic” in the chemical sense or “organic” as in shape/design. Økologisk parfyme is the natural phrase.

Does the adjective økologisk need to change form here?

It agrees in the usual way, but note that most adjectives ending in -sk don’t take a neuter -t:

Indefinite singular common: en økologisk parfyme
Indefinite singular neuter: et økologisk produkt (not “økologiskt”)
Definite singular: den økologiske parfymen/parfyma
Plural: økologiske parfymer/produkter

What does i byen imply—“in town” or a specific city?

Both are possible from context. i byen often means “in town (here)” in a general, local sense. If you need to specify which city, say i denne byen or name it: i Oslo.

Why not på byen?

For location inside a city you use i: i byen, i Oslo. på byen appears in the idiom dra på byen (“go out on the town”), but not for static location like this sentence.

Can I use a genitive instead: byens eldste oppskrift?

Yes: Dette parfymeriet har byens eldste oppskrift på økologisk parfyme. That’s idiomatic and puts slightly more emphasis on “the city’s.” Both versions are fine.

Can I rephrase with a relative clause using som?

Yes, for example:

Dette parfymeriet har oppskriften som er den eldste i byen.
Oppskriften som dette parfymeriet har, er den eldste i byen. The original with attributive superlative is just more concise.

Is har the best verb here? What about eier?

Use har for general possession/holding something: har oppskriften. eier means “owns (legally)” and sounds odd unless you’re talking about legal ownership/IP rights to the recipe.

What gender is oppskrift, and does that affect the sentence?

oppskrift is common gender in Bokmål, but many speakers also use the feminine form.

Common gender: en oppskrift – oppskriften
Feminine option: ei oppskrift – oppskrifta Your sentence could be either:
den eldste oppskriften (common gender)
den eldste oppskrifta (feminine) Both are correct; be consistent.

What are the plural forms I might need?

parfymeri (neuter): singular indef. et parfymeri, def. parfymeriet; plural indef. parfymerier, def. parfymeriene
oppskrift (common/fem.): plural indef. oppskrifter, def. oppskriftene Example plural sentence: Disse parfymeriene har de eldste oppskriftene på økologisk parfyme i byen.

Can I front i byen, and how does word order change?

Yes. Norwegian is verb-second (V2), so the finite verb stays in second position:

I byen har dette parfymeriet den eldste oppskriften på økologisk parfyme. Fronting i byen adds location emphasis but doesn’t change the meaning.