Hon ska skicka in blanketten så fort hon har fyllt i allt.

Ska is used to talk about something that is going to happen in the future, often with a sense of plan, intention, or expectation.

So Hon ska skicka in blanketten means something like:

• She is going to send in the form
• She will send in the form

In everyday Swedish, ska is very common for future meaning.

Skicka in is a verb + particle combination, often called a particle verb. It means send in, submit, or hand in.

• skicka = send
• skicka in = send in / submit

So skicka in blanketten means submit the form, not just physically send something somewhere.

A lot of Swedish verbs work like this:

• fylla i = fill in
• lämna in = hand in / submit
• skriva ut = print out

These combinations often have a more specific meaning than the base verb alone.

Blankett means form.

The ending -en makes it definite:

• en blankett = a form
• blanketten = the form

So blanketten is the form.

This is very common in Swedish: the definite article is usually attached to the end of the noun rather than being a separate word like English the.

Here så fort means as soon as.

So:

• så fort hon har fyllt i allt = as soon as she has filled in everything

It is not the same as så snart som möjligt.

• så fort = as soon as
• så snart som möjligt = as soon as possible

So så fort connects two actions in time, while så snart som möjligt means doing something with as little delay as possible.

Har fyllt i is the present perfect, literally has filled in.

Swedish often uses the present perfect after expressions like så fort when one future action must be completed before another future action happens.

So the logic is:

1. first she fills in everything
2. then she submits the form

That is why Swedish says:

• så fort hon har fyllt i allt

This is very similar to English:

• as soon as she has filled in everything

In more casual English, people often just say as soon as she fills in everything, but Swedish commonly uses the perfect here to emphasize completion before the next action.

Fyllt is the supine form of the verb fylla.

To make the present perfect in Swedish, you usually use:

• har
  • supine

For example:

• har fyllt = has filled
• har skrivit = has written
• har skickat = has sent

So:

• hon har fyllt i allt = she has filled in everything

This is one of the key patterns for Swedish perfect tenses.

Fylla i means fill in or fill out, especially when talking about a form, questionnaire, application, and so on.

• fylla = fill
• fylla i = fill in / fill out

So:

• fylla i blanketten = fill in the form

In this sentence, hon har fyllt i allt means she has filled in all the required information.

Both allt and allting can mean everything.

• allt is very common and neutral
• allting is also common, but a little fuller or more emphatic in some contexts

So:

• hon har fyllt i allt
• hon har fyllt i allting

Both are possible. In this sentence, allt sounds natural and concise.

Because Swedish normally needs an explicit subject in each clause.

The sentence has two clauses:

1. Hon ska skicka in blanketten
2. så fort hon har fyllt i allt

The second clause also needs its own subject, so Swedish says hon again.

English does the same here:

• She will send in the form as soon as she has filled in everything

You cannot normally leave out the second hon in standard Swedish.

Because så fort hon har fyllt i allt is a subordinate clause.

In Swedish subordinate clauses, the word order is often a bit different from main clauses. Here, the finite verb har comes after the subject hon:

• hon har fyllt i allt

That is normal subordinate-clause order.

Compare:

• Main clause: Hon ska skicka in blanketten
• Subordinate clause: så fort hon har fyllt i allt

This is an important pattern in Swedish grammar.

Yes, often you can.

• så fort hon har fyllt i allt
• så snart hon har fyllt i allt

Both can mean as soon as she has filled in everything.

There can be small differences in style:

• så fort is very common in everyday speech
• så snart can sound a little more formal or careful in some contexts

But in a sentence like this, both are natural.

Yes, it is completely natural.

Hon ska skicka in blanketten så fort hon har fyllt i allt is a normal, idiomatic way to say that she will submit the form once she has completed it.

A native speaker would understand it immediately, and it sounds standard and correct.

Yes. Depending on context, Swedish might also use:

• lämna in blanketten = hand in / submit the form
• skicka iväg blanketten = send off the form
• skicka blanketten = send the form

But skicka in blanketten is especially natural when talking about submitting a form to an office, authority, website, or organization.

So in this sentence, skicka in is a very good choice.