Learn Hardcore Norwegian: Stjernen er synlig i kveld.

Use the definite when a specific/identified star is meant (already known in context). Use the indefinite to introduce a new, unspecified star: En stjerne er synlig i kveld = “A star is visible tonight.”

Is Stjerna also correct?

Yes. In Bokmål, many nouns allow an optional feminine form:

Indefinite: ei stjerne
Definite: stjerna Both stjernen and stjerna are standard Bokmål. Nynorsk prefers the feminine forms by default.

How do I make the sentence plural?

Definite plural: Stjernene er synlige i kveld. (“The stars are visible tonight.”)
Indefinite plural: Stjerner er synlige i kveld. (“Stars are visible tonight.”) Norwegian often uses the definite plural for general groups, but both are possible depending on nuance.

Why doesn’t the adjective agree with the noun here? Shouldn’t it be something like “synlig(e)”?

In predicative position (after the verb “to be”), adjectives don’t change for gender in the singular:

Singular: Stjernen er synlig. / Huset er synlig.
Plural adds -e: Stjernene er synlige. So you only see the -e in the plural.

How would the adjective look before the noun (attributive)? Do I need “double definiteness”?

Yes. With an adjective before a definite noun, use a determiner + adjective + definite noun:

Definite: den synlige stjernen
Indefinite: en synlig stjerne
Neuter indefinite (note: -lig adjectives don’t take -t): et synlig tegn
Plural: synlige stjerner, de synlige stjernene

Can I move the time expression to the front? What happens to word order?

Yes. Norwegian main clauses are verb-second (V2):

Neutral: Stjernen er synlig i kveld.
Fronted time: I kveld er stjernen synlig. The finite verb (er) must be in second position.

Where does the negation go?

Place ikke after the finite verb:

Stjernen er ikke synlig i kveld. If you front the time, keep V2: I kveld er stjernen ikke synlig.
For “not yet,” use ennå/enda: Stjernen er ikke synlig ennå.

Is i kveld exactly “tonight”? How is it different from i natt?

i kveld = this evening/tonight (evening hours, before late night)
i natt = tonight/last night (during the night, late-night hours) So “visible tonight” in the evening is i kveld; in the night hours it’s i natt.

Can I say i kvelden, på kvelden, or om kvelden instead?

Don’t say i kvelden for “tonight.” The idiomatic form is i kveld.
om kvelden = “in the evenings” (habitual): Om kvelden er stjernene synlige.
på kvelden often means “in the evening (later that day)” in narratives/schedules, not specifically “tonight.” For “tonight,” prefer i kveld.

What’s the difference between er synlig and blir synlig?

er synlig = is (already) visible, a current state.
blir synlig = becomes/gets visible, a change of state: Stjernen blir synlig i kveld = “The star becomes visible this evening.”

Is Stjernen er i kveld synlig okay?

It’s grammatical but marked. The most natural placements for time are either at the end or at the beginning:

Natural: Stjernen er synlig i kveld. / I kveld er stjernen synlig.

Pronunciation tips?

stjernen: The j sounds like English “y,” so think “sty-.” Many speakers merge rn into a single retroflex sound. Roughly “STYER-nen.”
synlig: y is like German ü/French u. Final -g is often silent: “SEEN-lee” (with fronted vowel, not English “ee”).
kveld: kv as in “kv.” The d is silent for many speakers: “kvel(l).”

How do I say it in the past or future?

Past: Stjernen var synlig i går kveld.
Future/prediction: Stjernen blir synlig i kveld. / Stjernen vil være (eller: kommer til å være) synlig i kveld. Present with a time adverb also works for scheduled/expected future: I kveld er stjernen synlig.

Do common nouns get capitalized?

No. Norwegian doesn’t capitalize common nouns: stjernen, kveld. Capitalize only proper names (e.g., Nordstjernen if used as a name).