Påmeldingen er åpen.

Because -en is the definite ending, like the in English.

• påmelding = registration / sign-up
• påmeldingen = the registration / the sign-up

Norwegian often puts definiteness at the end of the noun instead of using a separate word before it.

So Påmeldingen er åpen literally looks like The registration is open.

For the same reason: Norwegian usually builds the into the noun itself.

So instead of:

• the registration

you often get:

• påmeldingen

You would only add a separate determiner in special cases, for example:

• den påmeldingen = that registration
• den åpne påmeldingen = the open registration
  
  • here Norwegian uses double definiteness because there is an adjective before the noun

But in Påmeldingen er åpen, the ending -en already does the job.

Because åpen agrees with a singular non-neuter noun.

In predicative position, after er, the adjective still agrees with the noun:

• en/ei påmelding er åpen
• et vindu er åpent
• flere vinduer er åpne

So here:

• påmeldingen is not neuter
• therefore the adjective is åpen, not åpent

A useful quick pattern is:

• common gender singular: åpen
• neuter singular: åpent
• plural: åpne

Because åpne is not the form used here.

You typically use åpne for:

• plural:
  Dørene er åpne = The doors are open
• some attributive uses before a noun:
  åpne spørsmål = open questions

But in Påmeldingen er åpen, the noun is singular, so åpen is correct.

Great question. In Bokmål, many nouns that are historically feminine can often be written either with feminine or masculine/common-gender endings.

So you may see both:

• påmeldingen
• påmeldinga

Both can be acceptable, depending on style and dialect preference.

In standard written Bokmål, påmeldingen is very common and completely natural.
So for a learner, Påmeldingen er åpen is an excellent form to learn.

Because er åpen means is open / is available, which is the natural idea here.

• Påmeldingen er åpen = registration is open
• Påmeldingen er åpnet = the registration has been opened / has been officially opened

So:

• åpen describes a state
• åpnet emphasizes an action or result

For websites, events, courses, and applications, er åpen is usually the most idiomatic choice.

Usually, Påmeldingen er åpen sounds more natural.

That is because the sentence is talking about the registration process as a specific thing: the registration.

Without the definite ending, Påmelding er åpen sounds less natural to many speakers. You are more likely to see alternatives such as:

• Påmeldingen er åpen
• Det er åpent for påmelding
• Påmelding er nå mulig = Registration is now possible

So as a learner, it is safest to use Påmeldingen er åpen.

It usually means sign-up, registration, or enrollment, depending on context.

Common contexts include:

• events
• courses
• competitions
• newsletters
• appointments

So påmelding is a practical everyday word for joining or registering for something.

Compared with registrering, påmelding often feels more like signing up for something specific, while registrering can sound a bit broader or more technical.

No. It is also used very naturally in a figurative sense.

Examples:

• Butikken er åpen = The shop is open
• Påmeldingen er åpen = Registration is open
• Søknadsportalen er åpen = The application portal is open

So åpen can describe access, availability, or an active period, not just something physically unclosed.

A rough learner-friendly pronunciation guide is:

POH-mel-ding-en er OH-pen

A few notes:

• å is a long vowel, somewhat like the vowel in British more, though not exactly the same
• melding has a clear mel sound
• er is often said very lightly in normal speech
• åpen has two syllables: OH-pen

If you want to sound natural, keep the rhythm smooth:

PÅmeldingen er Åpen

No, this is a very normal Norwegian sentence pattern:

• Påmeldingen = subject
• er = verb
• åpen = predicative adjective

So it follows the basic pattern:

subject + verb + complement

That makes it similar to English:

Registration is open.

If you move another element to the front, Norwegian changes the order in the usual V2 way:

• Nå er påmeldingen åpen = Now registration is open

But the original sentence itself is completely straightforward.

Yes, very natural.

It is exactly the kind of sentence you might see on:

• an event page
• a course website
• a school announcement
• a sign-up form

It sounds short, clear, and idiomatic. That makes it a very typical piece of practical Norwegian.