Min veninde sender en ansøgning til en stilling i byen, fordi hun gerne vil skifte job.

Because veninde is a common-gender noun in Danish. With singular common-gender nouns, you use min.

So: min veninde = my female friend
mit job = my job
mine venner = my friends

A very common thing to learn in Danish is that possessives change with the gender and number of the noun.

Danish does not use an indefinite article together with a possessive.

So you say: min veninde = my friend

Not: min en veninde

This works just like English, where you say my friend, not my a friend.

Veninde means female friend. It tells you that the friend is a woman or girl.

Compare: en ven = a friend, often a male friend
en veninde = a female friend

In modern usage, ven can sometimes be used more generally, but veninde clearly specifies that the friend is female.

Sender is the present tense of sende.

So: at sende = to send
sender = sends / is sending

Like English, Danish present tense can describe either a general fact or something happening now, depending on context. So sender could mean either sends or is sending here.

Because both ansøgning and stilling are common-gender nouns, so their indefinite singular article is en.

Examples: en ansøgning = an application
en stilling = a position

If they were definite, Danish would usually add the article as an ending: ansøgningen = the application
stillingen = the position

Here til links the application to the position it is for. In natural English, you would often say an application for a position, but Danish does not always use the same preposition as English.

This is something learners often have to get used to: prepositions do not match perfectly across the two languages.

Also compare: søge en stilling = apply for a position
ansøge om en stilling = apply for a position

So the exact preposition depends on the expression.

Because byen is the definite form of by.

So: en by = a town / a city
byen = the town / the city

Danish usually shows definiteness by adding an ending to the noun, instead of using a separate word like the.

Here i byen most naturally describes stilling.

So: en stilling i byen = a position in town / in the city

It is not most naturally understood as describing where she is sending the application from. It is describing the location of the position.

Gerne is a very common Danish word that often adds the idea of gladly, willingly, or would like to.

In this sentence, hun gerne vil skifte job gives a softer, more natural sense like: she would like to change jobs
or
she really wants to change jobs

Without gerne, hun vil skifte job sounds more direct and plain: she wants to change jobs.

Because fordi introduces a subordinate clause, and Danish subordinate clauses follow different word-order rules from main clauses.

Main clause: Hun vil gerne skifte job.

Subordinate clause: ... fordi hun gerne vil skifte job.

A useful beginner rule is: in a main clause, the finite verb often comes early in second position, but after words like fordi, Danish switches to subordinate-clause word order.

Because Danish modal verbs take the bare infinitive, without at.

So: vil skifte = wants to change
kan sende = can send
skal arbejde = must work / is going to work

This is similar to English: wants to change has to, but after modal verbs like can and will, English also uses a bare infinitive: can send, will change

Danish does that after modal verbs such as vil, kan, skal, må, and kunne.

Because skifte job is a very common expression meaning change jobs or change job in a general sense.

Danish often leaves the noun bare in set expressions like this when it is meant generally rather than as one specific object.

So: skifte job = change jobs
but
skifte til et nyt job = change to a new job
skifte jobbet = change the specific job

They are close in meaning, but not identical.

Stilling is often more formal and means a position or post, especially in hiring and employment contexts.

Job is broader and more everyday.

So this combination sounds natural: en ansøgning til en stilling = an application for a position
skifte job = change jobs

In other words, she is applying for a position because she wants to change her job.

Because fordi starts a subordinate clause.

In Danish, many writers put a comma before subordinate clauses. You may also see sentences without that comma, depending on the comma system or style being used.

So this is common: ..., fordi hun gerne vil skifte job.

But you may also see: ... fordi hun gerne vil skifte job.

Both can be acceptable, depending on the writing convention.

Yes, Danish normally needs the subject pronoun.

So you say: fordi hun gerne vil skifte job

Not just: fordi gerne vil skifte job

Unlike some languages, Danish does not usually drop the subject pronoun in ordinary sentences.

The letter ø does not have an exact English equivalent.

A rough way to think of it is: say something a bit like the vowel in British English bird, but round your lips more.

So in ansøgning, the ø is not like English o in go, and not like u in fun. It is its own Danish vowel, and it takes some practice to hear and produce clearly.