Learn Hardcore Finnish: Minä olen kipeä tänään, joten pysyn kotona.

Yes. The verb ending already shows the person, so Minä olen kipeä… can simply be Olen kipeä…. Keeping minä adds emphasis or contrast: Minä olen kipeä, mutta hän ei ole.

What’s the difference between kipeä and sairas?

kipeä: feeling unwell, in pain, or with a minor/temporary illness. Also used for sore body parts: Kurkku on kipeä.
sairas: ill/sick in a more general or more serious/medical sense. You’ll often hear both. At work, Olen sairaana can specifically mean you’re on sick leave.

Why is it kotona and not koti?

Finnish uses locative cases instead of prepositions.

kotona = at home (inessive)
kotiin = to home (illative)
kotoa = from home (elative) Also note vowel harmony: kotona ends with -a (not -ä) because o is a back vowel and i is neutral.

What exactly is pysyn, and how is pysyä conjugated?

It’s 1st person singular present of pysyä (to stay/remain).

minä pysyn
sinä pysyt
hän pysyy
me pysymme
te pysytte
he pysyvät Negative present: en pysy, et pysy, ei pysy, emme pysy, ette pysy, eivät pysy.

Difference between pysyä kotona and jäädä kotiin?

pysyä kotona: remain at home for a period; emphasizes continuity. Example: Aion pysyä kotona koko päivän.
jäädä kotiin: decide to stay home instead of going somewhere. Example: Jään kotiin tänään. In your sentence, pysyn kotona fits the idea of staying put for the day.

Is joten the same as “because”?

No. joten means “so/therefore” (result). koska means “because” (reason).

Result: Olen kipeä, joten pysyn kotona.
Reason: Pysyn kotona, koska olen kipeä. You can also use siksi (for that reason): Olen kipeä, siksi pysyn kotona.

Do I need the comma before joten?

Yes. It links two independent clauses, so a comma is standard: …, joten …. You could also split into two sentences: Olen kipeä tänään. Niinpä pysyn kotona.

Where can I put tänään? Is the word order flexible?

Yes. Common options:

Olen tänään kipeä, joten pysyn kotona.
Tänään olen kipeä, joten pysyn kotona.
Olen kipeä tänään, joten pysyn kotona. Fronting Tänään emphasizes “today” in contrast with other days. All are natural.

Why present tense pysyn if I mean the rest of today? Where’s the future tense?

Finnish doesn’t have a separate future tense. The present covers near-future plans when context (like tänään) makes the time clear. So pysyn can mean “I will stay.”

Why is kipeä in the base form? Shouldn’t it be in some case?

Predicative adjectives after olla are in nominative singular: Olen kipeä, Olen väsynyt, Olen iloinen. No article is used in Finnish, so you don’t add anything like “a” or “the.”

How do I say a body part is sore?

Use the body part + on kipeä:

Kurkku on kipeä / Kurkkuni on kipeä (my throat is sore) Colloquial: Mulla on kurkku kipee. For general malaise, stick with Olen kipeä.

Why kotona and not kodissa? Is kodissa ever used?

Kotona is the idiomatic “at home,” especially for your own home. Kodissa means “in a home/house” and is used when specifying someone’s home or the building itself:

Olen kotona. (I’m at home.)
Olen hänen kodissaan. (I’m in her home.)
Institutional: Asun palvelukodissa.

What are natural colloquial equivalents?

Very common in speech:

Mä oon kipee tänään, joten mä pysyn kotona. Also heard: Mä oon kipee tänään, niin pysyn kotona. (niin is informal for “so”.)

Pronunciation tips for y and ä, and syllables here?

y: front rounded vowel (like German ü, French u).
ä: like the vowel in English “cat.”
j: like English y in “yes.” Syllables: Mi-nä o-len ki-pe-ä tä-nään, jo-ten py-syn ko-to-na. Primary stress is on the first syllable of each word.

Can I start a sentence with joten?

In informal writing/speech, yes, to refer back to the previous sentence: Olen kipeä. Joten pysyn kotona. In formal text, prefer Siksi pysyn kotona or keep joten between the clauses.

Do I ever need a possessive suffix like kotonani?

Usually no—kotona already implies “at home,” typically your own. A possessive suffix adds emphasis or contrast:

Olen kotona. (neutral)
Olen kotonani. (at my home, as opposed to somewhere else) You’ll also see plural forms: kotonamme (at our home), etc.