Learn Hardcore Norwegian: Det er lurt å tenke på om en melding bør være privat eller offentlig før du sender den. - It is wise to think about whether a message should be private or public before you send it.

Lurt is an adjective meaning “wise, smart, sensible” here. Literally, Det er lurt å... means “It is smart to...” or “It is wise to...”.

Grammatically, this is a very common pattern in Norwegian:

Det er + [adjective] + å + [infinitive]
- Det er lurt å spare penger. – It is wise to save money.
- Det er vanskelig å forstå. – It is difficult to understand.

Here:

det = dummy/“empty” subject
er = is
lurt = smart, wise
å tenke = to think

So: Det er lurt å tenke... → It is smart to think...

Why do we need det at the beginning? Could we say Å tenke på om en melding bør være privat eller offentlig er lurt instead?

Norwegian, like English, normally wants a subject in the sentence. Det here is a dummy subject, similar to it in It is smart to think about....

Your alternative:

Å tenke på om en melding bør være privat eller offentlig er lurt.

is grammatically correct, but:

It sounds more formal and heavier, more like written or academic language.
The version with Det er lurt å... is more natural and typical in everyday speech.

So both are possible, but Det er lurt å... is the default, natural way to say it.

What is the function of å in å tenke?

Å is the infinitive marker, like “to” in English before a verb:

å tenke – to think
å spise – to eat
å sende – to send

So å tenke is the infinitive form “to think”, and å tenke på is “to think about”.

Why is it tenke på om and not just tenke om?

In Norwegian, when you “think about” something, you normally use tenke på:

Jeg tenker på problemet. – I’m thinking about the problem.
Det er lurt å tenke på det først. – It’s smart to think about it first.

In this sentence:

tenke på = think about
om en melding bør være privat eller offentlig = whether a message should be private or public (this is the thing you are thinking about)

You cannot just say tenke om here. Om in this sentence does not replace på; it introduces the clause meaning “whether/if”:

tenke på [noe] – think about something
tenke på om [setning] – think about whether/if [clause]

So på is required with tenke, and om is required to introduce the “whether”-clause. They do different jobs.

What does om mean here, and how is it different from hvis?

Here, om means “whether / if” in the sense of indirect question or doubt:

tenke på om en melding bør være privat eller offentlig
→ think about whether a message should be private or public

Om is used:

after verbs of thinking, asking, wondering, etc.:
- Jeg lurer på om han kommer. – I wonder if/whether he’s coming.
- Hun spør om du har tid. – She asks if you have time.

Hvis means “if” in the sense of condition:

Hvis han kommer, blir jeg glad. – If he comes, I’ll be happy.
Hvis det regner, blir vi inne. – If it rains, we’ll stay inside.

So in this sentence, hvis would be wrong, because it is not a condition (if X then Y), but what you are considering / wondering about. Therefore we use om.

What does bør express in en melding bør være privat eller offentlig? How is it different from skal or må?

Bør is a modal verb meaning “should / ought to” and expresses advice or recommendation, not strict obligation.

En melding bør være privat.
→ A message should be private (it’s recommended / wise).

Compare:

skal – shall / is going to (plan, intention, expected rule)
- Meldingen skal være privat.
  → The message must / is supposed to be private (a rule).
må – must / have to (necessity)
- Meldingen må være privat.
  → The message has to be private (necessary, no real choice).

So bør is softer and fits well with Det er lurt... (it’s wise, advisable).

Why is it en melding first, and then den later? Why not repeat meldingen?

En melding is the indefinite form: a message (introducing something new).

Later, instead of repeating the noun, Norwegian often uses a pronoun to refer back:

før du sender den – before you send it

Here:

melding is a common gender noun (en-ord).
The corresponding third-person singular pronoun is den (for en-words).

You could say før du sender meldingen, but:

Using den avoids repetition.
It’s very natural and typical in Norwegian, just like English uses it.

Why is the pronoun den and not det or denne at the end?

Norwegian pronouns agree with the grammatical gender of the noun:

melding is common gender (en-word).
The matching pronoun is den (common gender).

So:

en melding → den (it)
et brev → det (it)
en bil → den (it)

Denne means “this” and is a demonstrative, not a simple pronoun referring back in general:

den = it (that thing we just mentioned)
denne = this (this specific one, more pointing/emphatic)

In this context, we just need “it”, so den is correct.

Why are the adjectives privat and offentlig not changed for gender or definiteness here?

In the sentence:

en melding bør være privat eller offentlig

the adjectives privat and offentlig are used as predicate adjectives (after være – “to be”), describing the subject.

In this position (after være, bli, virke, se ut, etc.):

Adjectives do not take the -e ending for definiteness or common gender in the singular.
They stay in their basic form:
- Huset er stort. – The house is big.
- Bilen er rød. – The car is red.
- Meldingen er privat. – The message is private.

If the adjectives were before the noun (attributive), they would change:

en privat melding – a private message
den private meldingen – the private message

But after bør være, they remain privat / offentlig.

What word order rules are used in før du sender den?

Før is a subordinating conjunction meaning “before”. It introduces a subordinate clause:

før du sender den – before you send it

In Norwegian subordinate clauses, the normal order is:

[conjunction] + subject + finite verb + (objects/etc.)

So:

før (conjunction)
du (subject)
sender (finite verb)
den (object)

You do not use verb-second (V2) word order in this kind of clause.
So før du sender den is correct; forms like før sender du den would be wrong here.

Why is it sender (present tense) and not skal sende or a future form after før?

Norwegian often uses the present tense to talk about future time when the time is clearly indicated by another word (like før, når, i morgen, etc.):

Før du sender den – Before you send it (in the future)
Når jeg kommer hjem, lager jeg mat. – When I get home, I’ll make food.

After før, it is very natural to use the present tense:

Før du sender den
Not:
Før du skal sende den (possible, but feels more like “before you are going to send it”, more awkward in this context)

So sender here has a future meaning because of før.

Could we replace du with man to make the sentence more general? Would anything else change?

Yes, you can make it more general by using man (impersonal “one / people / you”):

Det er lurt å tenke på om en melding bør være privat eller offentlig før man sender den.

This means roughly: It’s wise to think about whether a message should be private or public before one/people/you send it.

Notes:

man is impersonal and generic, like “one” or informal “you” in English.
Nothing else in the sentence has to change here; den still refers to en melding.
In colloquial speech, some people use en instead of man in some dialects, but man is the standard written form.

Where would ikke go if I wanted to say “It’s not smart to think about…” or “before you don’t send it”?

Two main possibilities, depending on what you want to negate.

Negating “it is smart” (It’s not smart to think about this):

Det er ikke lurt å tenke på om en melding bør være privat eller offentlig før du sender den.
→ It is not smart to think about whether a message should be private or public before you send it.

Here, ikke comes after the finite verb er:

Det er ikke lurt...

Negating the sending (It’s smart not to send it publicly):

You would move ikke into the infinitive phrase, e.g.:

Det er lurt å ikke sende den offentlig.
→ It is smart not to send it publicly.

In your original sentence, før du ikke sender den is usually not what you want; it would literally be before you don’t send it, which is odd. The natural negation in your original structure is the first one: Det er ikke lurt...

Can I move før du sender den to the beginning of the sentence?

Yes. Før du sender den is an adverbial clause and can be moved. When you put it first, the main clause must still follow Norwegian V2 word order (finite verb in second position):

Før du sender den, er det lurt å tenke på om en melding bør være privat eller offentlig.

Structure of the main clause after the comma:

er (finite verb in 2nd position)
det (subject)
lurt å tenke på om en melding bør være privat eller offentlig (rest)

Both versions are correct:

Det er lurt å tenke på ... før du sender den.
Før du sender den, er det lurt å tenke på ...

The meaning is the same; the choice is about focus and style.