Learn Hardcore Norwegian: Vi må levere søknaden innen fredag. - We must submit the application by Friday.

Because må is a modal verb, and Norwegian modals take a bare infinitive (no å): må levere.
Use å with non-modals: trenger å levere, prøver å levere, liker å levere.

How strong is må compared to skal, bør, and trenger å?

må = must/need to (strong obligation/necessity).
skal = will/is supposed to (plan/arrangement or external obligation).
bør = should/ought to (recommendation).
trenger å = need to (practical need; not a modal).
Forms: må (present), måtte (past), har måttet (perfect).

What exactly does innen fredag mean? Is Friday included?

It means “by Friday,” inclusive. The deadline is no later than Friday (often end of day).
If you want “before Friday (not on Friday),” use før fredag.

Can I say før/på/til/senest fredag instead? What’s the difference?

før fredag = before Friday (not on Friday).
på fredag = on Friday.
til fredag = often “by Friday” in speech, but can be regionally ambiguous (“until Friday”); in formal writing, prefer innen.
senest (på) fredag = at the latest Friday (synonym of innen fredag).

Is levere the best verb here? What about levere inn and sende inn?

All work:

levere = deliver/submit (general).
levere inn = hand/turn in to an authority; slightly more explicit for “submit.”
sende inn = send in (esp. online/by mail).
Example: Vi må sende inn/lever(e) inn søknaden innen fredag are both natural.

Why is it søknaden (definite) and not en søknad?

Definite form signals a specific, known item (“the application”).
Forms of søknad:

Indefinite singular: en søknad
Definite singular: søknaden
Indefinite plural: søknader
Definite plural: søknadene

Is applikasjon a false friend here?

Yes. Applikasjon in Norwegian is usually “software app” (or “application of lotion”). For a job/school “application,” use søknad.

How would I say it in the passive voice?

Søknaden må leveres innen fredag. (The application must be submitted by Friday.)
Slightly different nuance: Søknaden må være levert innen fredag. (It must be in by Friday.)

Where does ikke go, and what’s the difference between må ikke and trenger ikke?

Placement: after the modal — Vi må ikke levere …
Meaning:
- må ikke = must not (prohibition).
- trenger ikke (å) = don’t need to (no obligation).
  Be careful: må ikke is not “don’t have to.”

What happens to word order if I start with the time phrase?

Norwegian is V2 (verb-second). If you front the time phrase, the finite verb stays second:
Innen fredag må vi levere søknaden.

How do I make the yes/no question “Do we have to submit the application by Friday?”

Invert subject and modal: Må vi levere søknaden innen fredag?
(No “do”-support in Norwegian.)

Any quick pronunciation tips for this sentence?

Vi ≈ “vee.”
må ≈ “mo” with a long vowel [moː].
levere stress on the second syllable: le-VE-re.
søknaden stress on first syllable: SØK-na-den; ø like German “ö.”
innen ≈ “IN-nen,” double n.
fredag ≈ “FREH-dag,” long e; final g may be light depending on dialect.
Tip: å ~ “aw” in “law” (longer/rounder), ø ~ French “eu” in “peur.”

Are days of the week capitalized in Norwegian?

No. Write fredag, not “Friday,” unless it starts a sentence.

How do I say “our application” here?

Most neutral: Vi må levere søknaden vår innen fredag. (possessive after the noun, noun in definite form)
More formal/emphatic: Vi må levere vår søknad innen fredag.

How do the tenses work if I want past or perfect?

må → måtte (past), har måttet (perfect).
levere → leverte (past), har levert (perfect).
Examples: Vi måtte levere søknaden innen fredag. / Vi har levert søknaden.

Is there a Nynorsk version?

Yes: Vi må levere/levere søknaden innan fredag.
Many prefer the -a infinitive in Nynorsk: Vi må levera søknaden innan fredag.

How do I specify a clock-time deadline?

Add the time after the day: Vi må levere søknaden innen fredag klokka 16.
Variants: innen fredag kl. 16, senest fredag klokka 16.