Katten kräktes i morse.

Because katten is the definite singular form of katt.

• katt = a cat / cat
• katten = the cat

In Swedish, the definite article is usually attached to the end of the noun rather than written as a separate word:

• en katt = a cat
• katten = the cat

So Katten kräktes i morse starts with the cat, not just cat.

Because katt is an en-word in Swedish.

Most common-gender nouns use:

• indefinite: en katt
• definite: katten

Compare:

• en hund → hunden
• en bil → bilen

If a noun is an ett-word, it would usually take -et instead:

• ett hus → huset

So the ending -en tells you both that the noun is definite and that katt is an en-word.

Yes. kräktes is the preterite (simple past) of kräkas, meaning to vomit / to throw up.

A few useful forms are:

• infinitive: kräkas
• present: kräks
• past: kräktes
• supine: kräkts

Examples:

• Katten kräks. = The cat is vomiting / vomits.
• Katten kräktes. = The cat vomited.
• Katten har kräkts. = The cat has vomited.

Because kräkas is not behaving like a completely regular verb in the past tense. Swedish verbs form the past in different patterns, and many common verbs have stem changes or less predictable forms.

So this is just something you learn as part of the verb’s principal forms:

• kräkas
• kräks
• kräktes
• kräkts

It is best to memorize it as a full set rather than trying to build it from a single rule every time.

i morse is a fixed expression meaning this morning or earlier this morning.

It refers specifically to the morning of the current day. It works as a time expression, like an adverbial.

Examples:

• Jag såg honom i morse. = I saw him this morning.
• Det regnade i morse. = It rained this morning.

So in your sentence, i morse tells you when the vomiting happened.

Because they do not mean exactly the same thing.

• i morse = this morning (the morning of today)
• på morgonen = in the morning / during the morning in a more general sense

Compare:

• Katten kräktes i morse. = It happened this morning
• Katten brukar sova på morgonen. = The cat usually sleeps in the morning

So i morse is the natural choice when you are talking about something that happened earlier today.

Because Swedish often uses the simple past directly, without an extra auxiliary, where English may use either vomited or has vomited depending on context.

Here:

• Katten kräktes i morse uses the simple past (preterite)

This is very natural in Swedish when talking about a completed event at a specific past time.

You could also see a perfect form in other contexts:

• Katten har kräkts. = The cat has vomited.

But with a clear finished-time expression like i morse, Swedish very often prefers the simple past.

The word order is the normal Swedish main-clause order:

subject + verb + time expression

So:

• Katten = subject
• kräktes = verb
• i morse = time adverbial

Swedish also has the V2 rule in main clauses, which means the finite verb comes in the second position.

That is why you can also say:

• I morse kräktes katten.

Here, i morse comes first, so the verb kräktes must still stay in second position, and the subject katten moves after it.

No, that would be incorrect in a normal main clause.

Because Swedish follows the V2 rule, if you begin with i morse, the finite verb must come immediately after it:

• correct: I morse kräktes katten.
• incorrect: I morse katten kräktes.

This is a very important Swedish sentence pattern to get used to.

A helpful approximate pronunciation is:

KREK-tes

A few points:

• ä is pronounced somewhat like the e in bed
• kr is pronounced together at the start
• the kt cluster is pronounced clearly
• the stress is on the first syllable: KRÄK-tes

And the whole sentence is approximately:

KATT-en KREK-tes i MOR-se

That is only an approximation for English speakers, but it is a useful starting point.

kräkas is a normal, standard Swedish verb. It is direct, but not especially rude. You can use it in everyday speech, medical contexts, or when talking about animals and people.

A more colloquial alternative is spy:

• Katten spydde i morse.

That also means The cat threw up this morning, but spy is a bit more informal.

So kräktes is perfectly fine and standard.

No. katten does not tell you the cat’s biological sex.

The -en ending here is grammatical, not natural gender. It simply shows that katt is an en-word and that the noun is definite.

So katten can refer to:

• a male cat
• a female cat
• a cat whose sex is unknown or irrelevant

If you specifically wanted to mention sex, you would usually need other words or context.

Yes. In English, both are possible translations depending on tone:

• vomited = more formal/clinical
• threw up = more conversational

Swedish kräktes itself is fairly neutral and standard, so the best English translation depends on the style of the translation, not on a big difference in the Swedish sentence itself.