Katten har på sig skyddskragen hemma.

Har på sig is a very common Swedish expression meaning is wearing / has on.

So:

• Katten har på sig skyddskragen hemma. = The cat is wearing the protective collar at home.

Even though har by itself usually means has, the full expression ha på sig means to wear.

Because ha and ha på sig mean different things.

• ha = have
• ha på sig = wear / have on

So:

• Katten har skyddskragen hemma would sound more like The cat has the protective collar at home.
• Katten har på sig skyddskragen hemma means the cat is actually wearing it.

That little combination på sig is what gives the meaning wearing.

In Swedish, sig is the third-person reflexive pronoun, and it is used for the subject whether that subject is a person or an animal.

In ha på sig, the sig is part of the standard expression:

• Jag har på mig = I am wearing
• Du har på dig = you are wearing
• Han/hon/katten har på sig = he/she/the cat is wearing

So sig does not mean the cat is doing something unusually human. It is just how Swedish forms this expression.

Swedish usually puts the definite article at the end of the noun as a suffix.

• en katt = a cat
• katten = the cat

So katten already includes the meaning the cat.

This is very common in Swedish:

• en bok → boken
• en hund → hunden
• en krage → kragen

For the same reason: it is the definite form.

• en skyddskrage = a protective collar
• skyddskragen = the protective collar

So the sentence is talking about a specific collar, not just any collar.

Also, skyddskrage is a compound noun:

• skydd = protection
• krage = collar

Together: skyddskrage = protective collar.

Because the sentence refers to a specific cat and a specific collar.

• katten = the cat
• skyddskragen = the protective collar

This is perfectly normal in Swedish. If you wanted a more indefinite meaning, you could say:

• En katt har på sig en skyddskrage hemma. = A cat is wearing a protective collar at home.

But the original sentence clearly points to known, specific things.

Because hemma means at home, while hem usually means home as a direction.

Compare:

• Katten är hemma. = The cat is at home.
• Katten går hem. = The cat goes home.

In your sentence, the meaning is location, not movement, so hemma is the correct choice.

Because Swedish often places adverbs of place, like hemma, later in the sentence, especially after the object.

So this order is very natural:

• Katten har på sig skyddskragen hemma.

It keeps the main information in a smooth order:

1. subject: Katten
2. verb phrase: har på sig
3. object: skyddskragen
4. place: hemma

You can move elements for emphasis in Swedish, but the original order is neutral and normal.

Yes, you could, but it is less natural in everyday speech for this situation.

• bär = carries / wears
• har på sig = is wearing / has on

For clothes, collars, glasses, and similar things, ha på sig is often the most natural everyday choice.

So:

• Katten har på sig skyddskragen hemma sounds very natural.
• Katten bär skyddskragen hemma is understandable, but a bit less conversational here.

Yes, har is present tense of ha.

Swedish usually does not need a separate progressive form like English is wearing. The plain present tense often covers both simple present and ongoing present, depending on context.

So:

• Katten har på sig skyddskragen hemma can naturally mean The cat is wearing the protective collar at home.

This is very common in Swedish:

• Jag äter. = I eat / I am eating
• Hon läser. = She reads / She is reading

The context tells you which meaning is intended.

You would normally use the indefinite form:

• Katten har på sig en skyddskrage hemma.

Compare:

• skyddskragen = the protective collar
• en skyddskrage = a protective collar

So the original sentence refers to a specific collar, while this version sounds less specific.

Yes. Swedish uses compound nouns very often, much more freely than English.

Here:

• skydd
  • krage = skyddskrage

English often writes these as separate words, but Swedish commonly joins them into one word.

This is something English speakers need to get used to. Other examples are:

• sjukhus = hospital
• fotbollsmatch = football match
• vinterjacka = winter jacket

So skyddskrage follows a very typical Swedish pattern.

No. It can be used for many things that are worn on the body, not just clothing.

For example:

• Hon har på sig en jacka. = She is wearing a jacket.
• Han har på sig glasögon. = He is wearing glasses.
• Katten har på sig skyddskragen. = The cat is wearing the protective collar.

So it works well for a collar like this too.