Jeg forstår overhovedet ikke, hvorfor appen ikke virker, når koden er rigtig.

Overhovedet ikke means not at all and adds strong emphasis.

• Jeg forstår ikke = I don’t understand
• Jeg forstår overhovedet ikke = I don’t understand at all

The word overhovedet is often used together with a negative word like ikke to strengthen it.

Because they negate two different parts of the sentence:

• Jeg forstår overhovedet ikke = I do not understand at all
• appen ikke virker = the app does not work

So the first ikke belongs to forstår, and the second ikke belongs to virker.

Because app is a common-gender noun in Danish:

• en app = an app
• appen = the app

If it were a neuter noun, the definite ending would usually be -et, but here the correct form is -en.

Because this is an indirect question embedded inside a larger sentence.

• Direct question: Hvorfor virker appen ikke?
• Indirect question: Jeg forstår ikke, hvorfor appen ikke virker.

In a direct question, Danish uses inversion: the verb comes before the subject.

• virker appen

In an indirect question, Danish does not use that inversion. Instead, the clause follows subordinate-clause word order:

• hvorfor + subject + ikke + verb
• hvorfor appen ikke virker

This is a very common thing learners notice.

Not by itself in this sentence. It is an embedded or indirect question.

It expresses the content of what the speaker does not understand:

• I don’t understand [why the app doesn’t work]

So it behaves like a subordinate clause, not like a standalone question.

Here når is closest to when, but in English the idea can overlap with if depending on context.

In this sentence, når koden er rigtig means something like:

• when the code is correct
• when the code is right
• sometimes almost if the code is correct

A useful contrast is:

• når = when / whenever / in situations where something is treated as real or expected
• hvis = if, especially for a more hypothetical condition

So når here suggests a real situation the speaker is talking about, not just a remote possibility.

Because adjectives in Danish agree with gender and number.

Here the noun is koden, from en kode, which is common gender singular. With a predicate adjective after er, common-gender singular uses the basic form:

• koden er rigtig

Compare:

• et svar er rigtigt = neuter singular
• koderne er rigtige = plural/definite

So rigtig is correct because kode is an en-word.

Yes. Rigtig can mean right or correct.

In everyday Danish, rigtig is very common. In a more formal or technical style, some speakers might also say korrekt:

• når koden er rigtig
• når koden er korrekt

Both are understandable. Korrekt can sound a bit more formal or precise.

Yes, often you can.

• appen virker ikke = the app doesn’t work
• appen fungerer ikke = the app doesn’t function

Both are natural. Virker is extremely common in everyday Danish for machines, devices, software, and systems. Fungerer is also fine, but can sound slightly more formal or technical in some contexts.

Because Danish normally uses commas to separate subordinate clauses from the main clause.

In this sentence:

• Jeg forstår overhovedet ikke, = main clause
• hvorfor appen ikke virker, = subordinate clause
• når koden er rigtig. = subordinate clause inside that larger structure

So the commas help show the clause boundaries.

Yes. Slet ikke also means not at all and is very common.

• Jeg forstår slet ikke ...
• Jeg forstår overhovedet ikke ...

Both are natural. Overhovedet ikke often sounds a bit more emphatic, while slet ikke is extremely common in everyday speech.