Learn Hardcore Norwegian: Vi må laste opp en kopi som vedlegg.

må = must / have to (strong necessity or obligation).
- Vi må laste opp … = We have to / must upload …
skal can mean:
- future plan/intention: Vi skal laste opp … = We are going to upload …
- sometimes obligation (especially if coming from rules/authority), but usually a bit weaker or more “scheduled” than må.
bør = should (advice, recommendation, weaker than må).
- Vi bør laste opp … = We should upload … (a good idea, but not absolutely necessary).

In this sentence, må clearly expresses a requirement, not just a plan or advice.

Why is it må laste opp and not må å laste opp?

With modal verbs in Norwegian (like kan, vil, må, skal, bør, måtte, skulle, ville):

You use the bare infinitive of the main verb, without å:
- Vi må laste opp …
- Jeg kan snakke norsk.
- Hun vil spise nå.

If there is no modal verb, you normally need å before an infinitive:

Jeg liker å laste opp filer.
Det er viktig å laste opp en kopi.

So: modal + bare infinitive (må laste opp), otherwise normally å + infinitive (å laste opp).

Why is laste opp two words? Is it one verb, and can the words be separated?

laste opp is a particle verb (or phrasal verb), similar to English load up / upload:

laste = to load
opp = up (a particle here; together they mean to upload)

It behaves as one verb in meaning, but is written as two words.

About separation:

With a noun object, both are possible (though the first is more common):
- Vi må laste opp en kopi.
- Vi må laste en kopi opp. (correct, but less common in many styles)
With a pronoun object, the pronoun normally goes between verb and particle:
- Vi må laste den opp. (not ✗laste opp den in neutral word order)

In the infinitive after a modal, you keep laste opp together as shown: må laste opp.

Where does ikke go if I want to say “We must not upload a copy as an attachment”? And how do I say “We don’t have to upload …” in Norwegian?

1. “We must not upload a copy as an attachment” (prohibition)
Use må ikke:

Vi må ikke laste opp en kopi som vedlegg.
= It is forbidden / we are not allowed to upload a copy as an attachment.

Word order: subject – V2 (må) – ikke – infinitive:

Vi må ikke laste opp …

2. “We don’t have to upload a copy as an attachment” (no obligation)
In Norwegian, må ikke is not “don’t have to”; it is “must not”.
For “don’t have to”, you normally use trenger ikke å (or behøver ikke å):

Vi trenger ikke å laste opp en kopi som vedlegg.
= We don’t need to / don’t have to upload a copy as an attachment.

So:

må ikke = must not (prohibited)
trenger ikke å / behøver ikke å = don’t have to / don’t need to (no obligation)

Why is it en kopi and not et kopi? What is the gender and plural of kopi?

kopi is (usually) a masculine noun in Bokmål:

Indefinite singular: en kopi = a copy
Definite singular: kopien = the copy
Indefinite plural: kopier = copies
Definite plural: kopiene = the copies

Some speakers treat many -i words as feminine in everyday speech (using ei), but the most standard form in Bokmål is masculine:

en kopi – kopien – kopier – kopiene

Why is there no article before vedlegg? Could I say som et vedlegg instead of som vedlegg?

som vedlegg here means as an attachment / in the role of an attachment.

When you use som to describe someone’s or something’s role, function, or capacity, Norwegian often drops the article:

Jeg jobber som lærer. = I work as (a) teacher.
Hun ble valgt som leder. = She was chosen as (the) leader.
Vi må laste opp en kopi som vedlegg. = We must upload a copy as an attachment.

You can say som et vedlegg:

Vi må laste opp en kopi som et vedlegg.

This is also correct, and can sound a bit more like “as one attachment” (slightly more specific or countable). som vedlegg is more neutral and common as a description of function.

What is the gender and the forms of vedlegg? How do I say “the attachment” and “the attachments”?

vedlegg is a neuter noun:

Indefinite singular: et vedlegg = an attachment
Definite singular: vedlegget = the attachment
Indefinite plural: vedlegg = attachments (same form as singular)
Definite plural: vedleggene = the attachments

Examples:

Jeg har lagt ved et vedlegg. = I’ve added an attachment.
Jeg åpnet vedlegget. = I opened the attachment.
E-posten har to vedlegg. = The email has two attachments.
Jeg har lest vedleggene. = I’ve read the attachments.

Can I change the word order and say Vi må laste en kopi opp som vedlegg?

This is grammatically possible, but it sounds less natural in many contexts.

Preferred word order with a noun object is:

Vi må laste opp en kopi som vedlegg. ✅ (most natural)

You can say:

Vi må laste en kopi opp som vedlegg. ✔ (grammatically OK, but less neutral/standard)

General tendencies:

Verb + particle + noun object is the most common:
- laste opp en kopi
With pronoun objects, pronoun usually goes between verb and particle:
- laste den opp, laste den opp som vedlegg

So your sentence with laste en kopi opp is understood and correct, but the original word order is more typical.

What does som mean here, and is it the same som used for “who/that/which” in relative clauses?

Yes, it’s the same word, but used in a different function.

som has two main uses:

Relative pronoun (who/that/which):
- Kopien som vi lastet opp, er feil.
  = The copy that we uploaded is wrong.
Comparative / role marker (as / like / than):
- Jeg jobber som lærer. = I work as a teacher.
- Vi må laste opp en kopi som vedlegg.
  = We must upload a copy as an attachment.

In your sentence, som introduces a role/function: the copy is being used in the role of an attachment.

How is må conjugated? Does it change with person, and how do I say this in the past?

In Norwegian, verbs do not change with person (no I must / he musts difference).
må is the present tense form for all persons:

jeg må, du må, han/hun må, vi må, dere må, de må

The past tense of må is måtte:

Vi måtte laste opp en kopi som vedlegg.
= We had to upload a copy as an attachment.

Perfect (have had to):

Vi har måttet laste opp en kopi som vedlegg.
= We have had to upload a copy as an attachment.

Future ideas are usually expressed with other constructions:

Vi kommer til å måtte laste opp en kopi.
= We are going to have to upload a copy.

What is the difference between vi and oss, and why is vi used here?

Norwegian distinguishes subject and object forms of pronouns, similar to we / us in English:

vi = we (subject form)
oss = us (object form)

vi is used as the subject of the sentence:

Vi må laste opp en kopi som vedlegg.
= We must upload a copy as an attachment.

oss would be used as an object:

De hjelper oss. = They are helping us.
Dette gjelder oss. = This concerns us.

So in your sentence, vi is correct because “we” are the ones doing the action.