Søknaden er allerede sendt inn.

Søknaden means the application.

The base noun is en søknad = an application.
When Norwegian adds -en to a common-gender noun, it usually makes it definite:

• en søknad = an application
• søknaden = the application

So -en here works like English the.

Because the sentence is focused on the application as the thing that has been submitted, not on the person who submitted it.

• Noen har sendt inn søknaden = Someone has submitted the application
• Søknaden er sendt inn = The application has been submitted / is submitted

This is a passive-style construction. In English, we often use has been submitted. In Norwegian, er sendt inn is very natural here.

So:

• har sendt inn = active, someone did it
• er sendt inn = passive/result-focused, the application is in the submitted state

It is basically one verbal expression: sende inn, which means to submit.

Literally:

• sende = send
• inn = in

But together, sende inn often means send in / submit.

So sendt inn is the past participle form of that phrasal verb:

• å sende inn = to submit
• sender inn = submits / is submitting
• sendte inn = submitted
• sendt inn = submitted

Even though inn is written separately, learners should think of sende inn as a single vocabulary item.

Because sende inn is a particle verb, and in Norwegian the particle often comes after the main verb part.

Here the participle is sendt, and the particle is inn, so:

• Søknaden er allerede sendt inn.

This is very normal word order.

You can think of it similarly to English phrasal verbs:

• The application has been sent in.

The in also comes late in the sentence.

Allerede means already.

In this sentence, it comes between er and sendt inn:

• Søknaden er allerede sendt inn.

That is a very natural position. It modifies the whole idea and shows that the submission happened before now, earlier than expected or earlier than some reference point.

A different placement may also be possible in some contexts, for example:

• Søknaden er sendt inn allerede.

But er allerede sendt inn is usually the most neutral and natural choice here.

Yes, functionally it is passive or very close to passive in meaning.

The important idea is that the sentence talks about what has happened to the application, not who did it.

Compare:

• Jeg har sendt inn søknaden. = I have submitted the application.
  active

• Søknaden er sendt inn. = The application has been submitted.
  passive/result-focused

In practical learning terms, it is best to understand er sendt inn here as has been submitted / is submitted.

Because sendt is the past participle, while sendte is the past tense.

• sendte = submitted / sent
  example: Jeg sendte inn søknaden i går. = I submitted the application yesterday.

• sendt = submitted / sent, used in perfect or passive-type constructions
  example: Søknaden er sendt inn.

So in er sendt inn, Norwegian needs the participle sendt, not the simple past sendte.

In English, the best translation is usually has been submitted.

Norwegian er sendt inn often emphasizes the present result: the application is now in a submitted state. Because of that, it can feel a bit like both:

• is submitted
• has been submitted

But in normal English, The application has already been submitted is the most natural translation.

So if you are trying to match the meaning in natural English, think:

• Søknaden er allerede sendt inn. = The application has already been submitted.

Yes. Søknaden har blitt sendt inn is also possible and clearly means The application has been submitted.

However, Søknaden er sendt inn is often shorter and very natural when the focus is on the current result.

Very roughly:

• Søknaden er sendt inn. = the application is submitted / has been submitted
• Søknaden har blitt sendt inn. = the application has been submitted

Both are correct, but er sendt inn is often the neat, idiomatic choice in this kind of situation.

The infinitive is å sende inn = to submit.

Useful forms:

• å sende inn = to submit
• sender inn = submits / is submitting
• sendte inn = submitted
• har sendt inn = has submitted
• er sendt inn = has been submitted / is submitted

Learning the whole expression å sende inn is better than learning just sende by itself for this sentence.

You usually put ikke after er:

• Søknaden er ikke sendt inn. = The application has not been submitted.

With allerede, a natural version is:

• Søknaden er ikke sendt inn ennå. = The application has not been submitted yet.

That is often more natural than trying to combine not and already directly.

Usually not if you mean the application.

• søknad by itself is the general noun application
• søknaden means the application

In this sentence, a specific application is meant, so the definite form is natural:

• Søknaden er allerede sendt inn.

If you said Søknad er allerede sendt inn, that would sound ungrammatical in normal Norwegian.

A rough pronunciation guide is:

• søk sounds somewhat like sirk without the r, but there is no exact English equivalent
• nad sounds roughly like nahd
• søknaden is approximately SØK-nah-den

The vowel ø is one English speakers often need to practice separately. It is a rounded front vowel, and English does not really have the same sound.

If helpful, break it into parts:

• søk
• na
• den

and then say it smoothly: søk-na-den.