Learn Hardcore Danish: Hun føler sig sikker, når hun ved, at der ikke er nogen fejl i planen. - She feels safe when she knows that there are no mistakes in the plan.

"Hun føler sig sikker" = She feels confident / secure.
"Hun føler sikker" is incorrect; after "føler" you need either:
- a reflexive pronoun (sig) plus an adjective, or
- a noun or some other complement (e.g. Hun føler smerte – She feels pain).

"Hun er sikker" is grammatically fine but slightly different in nuance:

"Hun er sikker" usually means She is sure / certain (about something).
"Hun føler sig sikker" emphasizes her internal feeling of security or confidence, not just intellectual certainty.

So "føler sig sikker" focuses on her felt state, not just a logical conclusion.

What exactly does the reflexive pronoun "sig" do in "føler sig"?

"Sig" is a reflexive pronoun used for 3rd person (he/she/it/they) in Danish.

Subject: hun (she)
Reflexive pronoun: sig (herself)

So "Hun føler sig sikker" literally means She feels herself secure, which in natural English is She feels secure/confident.

For different persons, the reflexive forms are:

jeg føler mig sikker – I feel secure
du føler dig sikker – you (singular) feel secure
han/hun/den/det føler sig sikker – he/she/it feels secure
vi føler os sikre – we feel secure
I føler jer sikre – you (plural) feel secure
de føler sig sikre – they feel secure

Notice how "sig" is only for 3rd person (han/hun/den/det/de). It shows that the feeling is directed back at the subject.

Why is the verb order "Hun føler sig sikker" and not "Hun sig føler sikker"?

Danish main clauses use V2 word order: the finite verb is always in second position.

In "Hun føler sig sikker":

Hun – subject (1st position)
føler – finite verb (2nd position)
sig – reflexive pronoun (3rd)
sikker – adjective (4th)

You cannot move "sig" in front of "føler". The verb must stay second:

✅ Hun føler sig sikker.
❌ Hun sig føler sikker.

The same V2 rule applies in most main clauses in Danish.

Why is it "når hun ved" and not "når ved hun"?

"Når" introduces a subordinate clause (a dependent clause). In Danish subordinate clauses, the verb does not go in second position; instead, the normal order is:

Conjunction – Subject – Verb – (other elements)

So:

✅ når hun ved (when she knows)
- når – conjunction
- hun – subject
- ved – verb
❌ når ved hun

The V2 rule (verb in 2nd position) is for main clauses, not for subordinate clauses after "når", "at", "fordi", etc.

Example contrast:

Main clause: Hun ved det. (She knows it.) – verb is 2nd.
Subordinate: når hun ved det (when she knows it) – conjunction first, then subject, then verb.

What is the function of "der" in "at der ikke er nogen fejl i planen"?

Here "der" is a kind of dummy/expletive subject, similar to English "there" in sentences like There are no errors in the plan.

"at der ikke er nogen fejl i planen"
literally: that there not are any errors in the plan

You could think of it as:

der er fejl – there are errors
der ikke er fejl – there are no errors

So "der" is not a place (not there as in a location). It’s a grammatical subject placeholder used in existential sentences (there is / there are).

Why is the negation "ikke" placed before "er" in "der ikke er nogen fejl"?

In subordinate clauses, the standard order is:

(Conjunction) – Subject – (Adverbs like "ikke") – Verb – (Other elements)

So in "at der ikke er nogen fejl":

at – conjunction
der – (dummy) subject
ikke – negation adverb
er – verb
nogen fejl – object / complement

That’s why you get:

✅ at der ikke er nogen fejl
❌ at der er ikke nogen fejl

In a main clause, you would say:

Der er ikke nogen fejl. – There are no errors.
(Here the verb is second, then ikke.)

What is the difference between "når" and "da"? Could I say "da hun ved" instead of "når hun ved"?

You cannot say "da hun ved" here; that would be wrong.

Basic rule:

når = when / whenever for present or future situations, or repeated/general situations.
da = when for one specific event in the past.

In this sentence, we talk about something that is generally true whenever the condition is met:

Hun føler sig sikker, når hun ved, at ...
= Whenever she knows that there are no errors in the plan, she feels secure.

Examples:

Jeg bliver nervøs, når jeg skal tale foran mange mennesker.
(Repeated/general: I get nervous when I have to speak in front of many people.)
Jeg blev nervøs, da jeg skulle tale foran klassen i går.
(One specific time in the past.)

What’s the difference between "ikke nogen fejl" and "ingen fejl"?

Both basically mean "no errors" / "no mistakes", but:

"ingen fejl" is the more common, more natural everyday expression.
"ikke nogen fejl" is also correct and can sound a bit:
- more emphatic,
- or sometimes a bit more formal or careful in tone.

You can say:

Der er ingen fejl i planen.
Der er ikke nogen fejl i planen.

In many contexts, they are practically interchangeable. Learners are usually safe using "ingen fejl" most of the time.

Why is "fejl" not plural here? How can "fejl" mean both "mistake" and "mistakes"?

"Fejl" is one of those Danish nouns that has the same form in singular and plural:

en fejl – one error / mistake
flere fejl – several errors / mistakes

So "fejl" by itself doesn’t tell you whether it is singular or plural; you see that from context or from the determiner:

en fejl – singular
ingen fejl – no error(s) (usually understood as plural: no errors)
mange fejl – many errors

In "ingen fejl i planen" or "ikke nogen fejl i planen", it is understood as “no errors” (plural concept), even though the word "fejl" stays the same.

Why is it "i planen" and not "på planen" or "af planen"?

The preposition "i" is used because we think of the plan as a content or structure that can contain mistakes:

"fejl i planen" – errors in the plan (within its content / design)

Some contrasts:

i – in/inside (content, enclosed space, or part of something)
på – on (surface, schedule, list, etc.)
af – of / from (often expresses origin, part of, or possession in some cases)

You might see:

ændringer i planen – changes in the plan
punkter på planen/dagsordenen – items on the plan/agenda

But for errors in how the plan is made, "fejl i planen" is the normal phrase.

Why is it "planen" with -en at the end and not "den plan"?

Danish usually marks definiteness by adding a suffix to the noun:

en plan – a plan (indefinite)
planen – the plan (definite)

You can also have a double definite structure with an adjective:

den gode plan – the good plan
den oprindelige plan – the original plan

But if there is no adjective, the normal definite form is the suffix only:

✅ fejl i planen – errors in the plan
❌ fejl i den plan (sounds incomplete; you’d expect an adjective: i den plan, vi lavede i går / i den oprindelige plan).

So "planen" is simply "the plan" in its ordinary definite form.

Why do we put commas before "når" and "at" in this sentence?

The sentence is:

Hun føler sig sikker, når hun ved, at der ikke er nogen fejl i planen.

There are two subordinate clauses:

når hun ved, at der ikke er nogen fejl i planen (introduced by når)
at der ikke er nogen fejl i planen (introduced by at)

Traditional Danish comma rules (and also the most common style taught to learners) say:

Put a comma before subordinate clauses introduced by words like "når", "fordi", "at", etc.

So:

Main clause: Hun føler sig sikker,
Subordinate clause 1: når hun ved,
Embedded subordinate clause 2: at der ikke er nogen fejl i planen.

There is a modern “new comma” system where some commas can be omitted, but for learners it’s usually safest to keep the commas before "når" and "at" as in this sentence.

Does the adjective "sikker" change form depending on gender or number here?

No. After "føler sig", the adjective stays in its base form, regardless of gender and number:

Hun føler sig sikker. – She feels secure.
Han føler sig sikker. – He feels secure.
De føler sig sikre. – They feel secure.

Notice:

Singular: sikker
Plural: sikre (when it directly follows a definite article or a plural noun: de sikre løsninger – the safe solutions)

But after "føler sig", you usually use the base form:

føler sig sikker
føler sig træt
føler sig glad

Could you rephrase the sentence using "sikker på"? Would that change the meaning?

Yes, a very natural variant is:

Hun føler sig sikker på, at der ikke er nogen fejl i planen.

The meaning shifts slightly:

Hun føler sig sikker – She feels secure/confident (more about her general feeling of safety).
Hun føler sig sikker på, at ... – She feels certain that there are no errors in the plan (emphasis on mental certainty about a specific fact).

So:

Original: focuses on her sense of security when she knows the plan is error-free.
With "sikker på, at": focuses more on her conviction that the plan has no errors.