Jeg aner det ikke.

Aner is the present tense of at ane.

In this sentence, at ane means something like to have even the slightest idea or to have a clue. So Jeg aner det ikke is stronger than a plain I don’t know. It is closer to:

• I have no idea
• I haven’t got a clue

So even if the basic meaning is already given, it helps to know that ane adds a sense of not knowing at all.

Both can mean I don’t know, but they are not exactly the same in tone.

• Jeg ved det ikke = I don’t know
• Jeg aner det ikke = I have no idea / I haven’t got a clue

So aner is usually a bit stronger and often a bit more informal or emphatic.

If you simply want a neutral, standard way to say I don’t know, Jeg ved det ikke is very common.
If you want to stress total lack of knowledge, Jeg aner det ikke works very well.

The dictionary form is at ane.

Here are the forms you are most likely to meet:

• at ane = to have a clue / to sense faintly
• aner = have a clue / know at all (present tense)
• anede = had no idea / didn’t know at all (past tense)
• har anet = have had any idea / have known at all

So:

• Jeg aner det ikke = I have no idea
• Jeg anede det ikke = I had no idea

Det means it, and it refers to the thing you do not know.

So the structure is basically:

• Jeg = I
• aner = have any idea about / know at all
• det = it
• ikke = not

In English, we also often say I don’t know it, but in natural English we usually just say I don’t know. In Danish, det is very normal when referring to a specific thing already understood from context.

For example:

• Ved du, hvornår toget går? = Do you know when the train leaves?
• Nej, jeg aner det ikke. = No, I have no idea.

Here, det refers to when the train leaves.

This is normal Danish word order.

In a main clause, ikke usually comes after the finite verb and after certain objects or pronouns, not directly before the verb the way not often does in English.

So:

• Jeg aner det ikke

not:

• Jeg ikke aner det in a normal main clause

A rough pattern is:

• subject + verb + object + ikke

That is why ikke comes last here.

Normally, no. Jeg aner det ikke is the natural word order.

With det as the object, Danish strongly prefers:

• Jeg aner det ikke

not:

• Jeg aner ikke det

You may sometimes hear Jeg aner ikke ... when no separate det follows, for example:

• Jeg aner ikke, hvad han mener. = I have no idea what he means.
• Jeg aner ikke hvorfor. = I have no idea why.

So ikke can come directly after aner when what follows is a clause, but with the pronoun det, the normal version is Jeg aner det ikke.

Yes, sometimes.

If the context is clear, Danes may simply say:

• Jeg aner ikke.

That means I have no idea.

But Jeg aner det ikke is also very common, especially when referring back to something specific already mentioned.

So both are possible, depending on context:

• Hvad tid kommer hun? = What time is she coming?
• Jeg aner ikke. = I have no idea.

or

• Ved du det? = Do you know that / do you know?
• Nej, jeg aner det ikke. = No, I have no idea.

It is completely normal everyday Danish. It is not rude, but it is a bit more expressive than Jeg ved det ikke.

You can think of it like this:

• Jeg ved det ikke = neutral
• Jeg aner det ikke = more emphatic, everyday, slightly informal
• Det ved jeg ikke = also very common, often a neutral reply with slight focus on that

So Jeg aner det ikke is fine in conversation, messages, and most everyday situations.

Pronunciation in Danish varies by speaker and region, but a rough guide is:

• Jeg ≈ yai or yigh
• aner ≈ EH-nuh
• det ≈ deh or sometimes very reduced
• ikke ≈ IG-uh or eg-uh

A very rough English-friendly approximation might be:

• yai EH-nuh deh IG-uh

But Danish pronunciation is often much softer and more reduced than spelling suggests.

A few useful notes:

• jeg is often not pronounced the way learners expect from the spelling
• r in aner is usually weak
• det is often unstressed
• ikke is a very common word, and its spoken form is often reduced

Yes. It works perfectly well as a full answer.

For example:

• Hvor bor han nu? = Where does he live now?
• Jeg aner det ikke. = I have no idea.

Danish often allows short, complete replies like this, just as English does.

You could also shorten it further in speech:

• Aner det ikke. = No idea / Haven’t got a clue.

That is more casual because it drops jeg.

The past tense is:

• Jeg anede det ikke. = I had no idea. / I didn’t know.

Examples:

• Jeg anede det ikke, før du sagde det. = I had no idea until you said it.
• Hun anede det ikke. = She had no idea.

So if you learn aner, it is useful to learn anede too.

No, but this expression is one of the most common uses for learners.

You may also see ane in sentences like:

• Jeg aner ikke, hvor han er. = I have no idea where he is.
• Kan du ane et lys derovre? = Can you make out a light over there?
• Jeg anede, at noget var galt. = I sensed that something was wrong.

So ane can mean either:

• to have a clue / know at all
• to sense faintly / make out

In Jeg aner det ikke, it has the first meaning.

Because Danish does not use do-support the way English does.

English says:

• I do not know
• I don’t know

But Danish simply negates the main verb with ikke:

• Jeg ved ikke
• Jeg aner det ikke

So Danish does not need an extra verb corresponding to English do here. That is a very common difference between the two languages.