Learn Hardcore Finnish: Minäkin teen listan, jossa on yksi lupaus jokaiselle kuukaudelle joulukuusta tammikuuhun. - I also make a list that has one promise for each month from December to January.

Minäkin teen listan = I also make a list (someone else is making a list, and I do it too).
Minä teen myös listan = roughly the same, but myös is a separate word; it’s a bit more neutral and written-style.
Myös minä teen listan = I, too, make a list (slightly more emphasis on I).

Attaching -kin to different words changes the focus:

Minäkin teen listan = I also will make one.
Minä teenkin listan (with stress on teenkin) = Turns out I will (after all) make a list; can sound a bit like a correction or surprise.

Why is it teen listan and not teen lista? What is that -n on listan?

The -n in listan marks the object in the accusative (or “total object”) form.

Compare:

teen listan = I make the whole list (a complete, bounded action; you intend to finish the list).
teen listaa = I am (in the process of) making a list / I work on a list (ongoing, not-complete, or unbounded).

In this sentence, you’re talking about creating a specific, finished list of promises, so Finnish uses the total object form: listan.

Why is there a comma before jossa? Is that a special kind of clause?

Yes. The part jossa on yksi lupaus… is a relative clause describing listan.

Minäkin teen listan, jossa on…
= I also make a list which has…

In Finnish, a comma is normally used before a relative clause introduced by joka / mikä and their forms (like jossa). So the comma here is standard punctuation to separate the main clause from the relative clause.

What exactly does jossa mean, and how is it different from missä?

Both jossa and missä can translate to in which / where, but they’re used differently.

jossa is a relative pronoun form of joka:
- joka = which / that / who
- jossa = in which
It refers back to a specific noun:
- teen listan, jossa on yksi lupaus…
  = I make a list *which has one promise…
  (*jossa refers to lista.)
missä is a question/relative word for where / in which place:
- Missä on lista? = Where is the list?
- It isn’t directly tied to a specific noun in the same grammatical way as jossa is here.

In this sentence, you need jossa because you are saying “a list which has …”, not asking “where” something is.

Why is it jossa on yksi lupaus and not jossa yksi lupaus on? Does the word order matter?

Both word orders are grammatically possible, but jossa on yksi lupaus is the natural, neutral one here.

Finnish often uses the pattern:

jossA on [something] = there is [something] in which… / which has [something]

So:

jossa on yksi lupaus = which has one promise / in which there is one promise

If you say:

jossa yksi lupaus on, you’re putting more emphasis on yksi lupaus (almost like stressing “the one promise that is there”). It sounds marked, less neutral.

So the given word order is the standard existential structure: [place] + on + [thing].

Why is it yksi lupaus (nominative) after on and not yhden lupauksen?

In jossa on yksi lupaus, the structure is an existential clause: it tells that something exists in a certain place.

In Finnish existential sentences, the thing that exists is usually in the nominative:

Huoneessa on tuoli. = There is a chair in the room.
Listassa on yksi virhe. = There is one mistake in the list.
Jossa on yksi lupaus = in which there is one promise.

If lupaus were an object of some verb (like I make / I fulfill a promise), you would see object cases (e.g. yhden lupauksen).
Here it’s not an object; it’s simply something that exists in the list, so nominative yksi lupaus is used.

What case is jokaiselle kuukaudelle, and why is -lle used here?

Jokaiselle kuukaudelle is in the allative case (ending -lle).

jokainen kuukausi = every month (basic form)
jokaiselle kuukaudelle = for each month / to each month

The allative (-lle) often expresses:

to / onto (a direction)
for (the benefit of) someone or something

Here it means “for each month”:

yksi lupaus jokaiselle kuukaudelle
= one promise for each month.

So -lle is used because the promises are assigned to the months, as if given to each month.

How does jokaiselle kuukaudelle differ from joka kuukausi?

They’re related in meaning but not identical:

joka kuukausi = every month
- Used as an adverbial of time (how often):
  - Teen jotain joka kuukausi. = I do something every month.
jokaiselle kuukaudelle = for each month
- Focuses on distribution: each month gets one item (here, one promise).

In the original sentence:

yksi lupaus jokaiselle kuukaudelle
= You have a set of promises, and you are conceptually giving one promise to each month in the range December–January.

If you said:

Teen yhden lupauksen joka kuukausi = I make one promise every month (habitual action), rather than preparing a list containing them in advance.

Could the order be Minäkin teen listan, jossa on jokaiselle kuukaudelle yksi lupaus? Does that change the meaning?

Yes, you can say:

Minäkin teen listan, jossa on jokaiselle kuukaudelle yksi lupaus.

It keeps the same basic meaning. The difference is subtle, mainly in emphasis:

…jossa on yksi lupaus jokaiselle kuukaudelle
= slightly more focus on the number (one promise), and then clarifies for each month.
…jossa on jokaiselle kuukaudelle yksi lupaus
= slightly more focus on the distribution (for each month), and then says it’s one.

Both are natural. The original is maybe a little more common or “default” sounding.

What does joulukuusta tammikuuhun literally mean, and why those endings -sta and -hun?

Joulukuusta tammikuuhun literally means from December to January.

joulukuu = December
- joulukuusta = from December (elative case, -sta / -stä = “out of / from”)
tammikuu = January
- tammikuuhun = to January (illative case, -hVn pattern here: -hun)

So the from–to pattern with times is often:

jostakin johonkin
e.g. maanantaista perjantaihin = from Monday to Friday
kello kolmesta kello viiteen = from three o’clock to five o’clock
joulukuusta tammikuuhun = from December to January

Here -sta (elative) marks the starting point, and -hun (illative) the end point.

Does joulukuusta tammikuuhun include both December and January? How many months are we talking about?

Grammatically, joulukuusta tammikuuhun just says “from December to January”; it doesn’t specify inclusivity mathematically the way English sometimes worries about it.

Interpretation depends on context:

It could mean December and January only (2 months).
Or it could mean a span crossing a year boundary, like from this year’s December to next year’s January, potentially including several months in between (if specified more clearly elsewhere).

If someone wanted to talk about a full normal calendar year of promises, they’d more likely say:

tammikuusta joulukuuhun = from January to December (12 months)

So, strictly from this sentence alone, we only know it’s a period running from some December to some January, and each month in that span gets one promise.

Could you also say joulukuusta tammikuuseen, or is tammikuuhun the only correct form?

Tammikuuhun is the correct illative form of tammikuu.

tammikuu → stem tammikuU- → tammikuuhun

The form tammikuuseen would suggest the base word is tammikuusi, which doesn’t exist. The -seen illative is used e.g. with words like:

kuusi (spruce/six) → kuuseen
uusi (new) → uuteen

But tammikuu (January) follows the kuu → kuuhun pattern. So in correct Finnish:

joulukuusta tammikuuhun ✅
joulukuusta tammikuuseen ❌

Could I drop Minä and just say Minäkin teen… as Mäkin teen listan… in spoken language?

Yes. In spoken Finnish, it’s very common to use mä instead of minä:

Mäkin teen listan, jossa on yksi lupaus jokaiselle kuukaudelle joulukuusta tammikuuhun.

Here:

mä = colloquial for minä
mäkin = I also / me too in spoken style

The grammar with -kin works the same; only the pronoun’s form changes to the colloquial version.