Learn Hardcore Swedish: Vilken färg har din jacka idag?

In questions, Swedish normally uses vilken/vilket/vilka when you are asking about a specific item or choice related to a noun, here färg (colour).
So Vilken färg …? literally means Which colour …?.

Vad is more general (what?), and you would not say ✗ Vad färg har din jacka? in standard Swedish. For colours, the fixed pattern is Vilken färg …?.

Why is it vilken and not vilket or vilka?

Vilken/vilket/vilka must agree with the grammatical gender and number of the noun that follows:

vilken – with en-words in singular
vilket – with ett-words in singular
vilka – with plural nouns

Since färg is an en-word (en färg), you must use vilken → Vilken färg …?.
If the noun were an ett-word, you would use vilket, e.g. Vilket språk talar du?

Why does the sentence say har (has) instead of är (is) for colour?

Literally, Vilken färg har din jacka idag? is Which colour has your jacket today?

In Swedish, it is very common to talk about colours with har + färg:

Vilken färg har bilen? – What colour is the car?
Huset har gul färg. – The house is yellow.

You can say Din jacka är blå, but when you are asking about the colour, the natural pattern is Vilken färg har X?, not Vilken färg är X?.
✗ Vilken färg är din jacka? sounds odd or foreign-influenced to most native speakers.

Why is the word order har din jacka and not din jacka har?

Swedish main clauses follow the V2 rule: the finite verb is always in second position in the sentence.

Here, the first element is the question word phrase Vilken färg, so the finite verb har must come next:

Vilken färg – first element
har – verb in second position
din jacka idag – the rest of the sentence

Putting din jacka before har (✗ Vilken färg din jacka har idag?) breaks the V2 rule and is ungrammatical in standard Swedish.

Why is it din jacka and not ditt jacka or dina jacka?

Swedish possessive pronouns agree with the gender and number of the noun they describe, not with the owner.

For du (you, singular), the forms are:

din – with singular en-words (e.g. din jacka, din bok)
ditt – with singular ett-words (e.g. ditt hus, ditt rum)
dina – with plural nouns (e.g. dina jackor, dina böcker)

Since jacka is an en-word in singular (en jacka), you must say din jacka.

Could I say jackan instead of din jacka? For example, Vilken färg har jackan idag?

Yes, Vilken färg har jackan idag? is grammatically correct and natural.
The difference is:

din jacka – specifically your jacket
jackan – the jacket, which both speaker and listener are assumed to know about from context (for example, the only jacket in the conversation or the one we can see).

So both are fine, but din jacka makes it explicit that we mean your jacket.

Where can I put idag in the sentence, and is i dag different from idag?

In this sentence, the most natural positions are:

Vilken färg har din jacka idag?
Vilken färg har din jacka i dag?

Idag and i dag mean exactly the same thing (today). Modern Swedish usually writes it as one word (idag), but i dag is also accepted.

You can sometimes move idag to the front for emphasis:

Idag, vilken färg har din jacka? – more marked, with a stronger focus on today.

Are there other natural ways to ask the same thing in Swedish?

Yes, some common alternatives are:

Vilken färg har du på din jacka idag? – literally: Which colour do you have on your jacket today?
Vad har din jacka för färg idag? – literally: What colour does your jacket have today?

All of these mean essentially What colour is your jacket today?
The original Vilken färg har din jacka idag? is short, neutral, and very common.

What is the difference between jacka, kappa, rock, and similar words?

These words all refer to outerwear but in different styles:

jacka – a general jacket, usually waist- or hip-length (e.g. a winter jacket, a leather jacket).
kappa – a coat that is typically longer, often worn by women (but can be unisex).
rock – a longer overcoat, more formal or traditional, often associated with men.

So din jacka is most naturally your jacket, not a long formal coat.

How do you pronounce färg, jacka, and idag?

Approximate pronunciations (in rough English-style writing):

färg – roughly like “fehr(y)”, with:
- ä like in English “bed”, but a bit longer,
- rg often sounding a bit like “ry” in many accents.
jacka – like “yacka”:
- Swedish j before a, o, u, å is usually like English y (as in yes).
idag – roughly “ee-dahg”:
- stress on the second syllable: i-DAG.

Listening to native audio is very helpful, because Swedish r and combinations like rg can vary quite a bit between dialects.

Is the sentence formal or informal? Would I say this to anyone?

The sentence is neutral informal. The pronoun din corresponds to du, which is the standard you in modern Swedish and is used with almost everyone, even in many professional contexts.

You can say Vilken färg har din jacka idag? to friends, family, colleagues, or strangers without it sounding rude. The tone is friendly and casual, not particularly formal.