Learn Hardcore Finnish: Kirjoitan tärkeät asiat ylös muistilapulle. - I write the important things down on a sticky note.

In this sentence ylös is a verb particle that combines with kirjoitan to form a kind of phrasal verb: kirjoittaa ylös ≈ “to write down / jot down / note down”.

Literally, ylös means “up”, but in this combination it doesn’t keep a clear spatial meaning.
Finnish often uses ylös or pois, etc., as particles that change or refine the meaning of the verb, similar to English phrasal verbs (write down, take off, put away).

So kirjoitan tärkeät asiat ylös is best understood as one unit: “I write the important things down.” The “up” idea is no longer felt strongly by native speakers in this expression.

Can I leave out ylös and just say Kirjoitan tärkeät asiat muistilapulle? Does the meaning change?

Yes, you can leave out ylös:

Kirjoitan tärkeät asiat muistilapulle.
= “I write the important things (on)to a note.”

Without ylös, the sentence is still perfectly natural and understandable. The difference is subtle:

With ylös:
Emphasizes the act of recording something so it won’t be forgotten (“write down”).
Without ylös:
More neutral “I write the important things on a note.” The context will still usually imply that you’re doing it to remember them.

In many contexts, both versions can be used interchangeably.

Why is tärkeät asiat in this form and not partitive, like tärkeitä asioita?

Tärkeät asiat is in the nominative plural and functions as a total object:

tärkeä → tärkeät (plural nominative of the adjective)
asia → asiat (plural nominative of the noun)

A total object is used when the action is seen as complete or affecting a whole, defined set of things. Here, it suggests:

“I (will) write down the important things (all of them / the ones we have in mind).”

If you used partitive plural tärkeitä asioita, it would suggest an indefinite amount or an incomplete action:

Kirjoitan tärkeitä asioita ylös.
≈ “I (tend to) write down important things (some important things, not a specific complete set).”

So tärkeät asiat implies a more definite, “all of these” feel.

What exactly would be the nuance difference between tärkeät asiat and tärkeitä asioita in this sentence?

Kirjoitan tärkeät asiat ylös muistilapulle.
⇒ There’s a specific set of important things (already defined in context) and I write them all down. The action is viewed as complete and bounded.
Kirjoitan tärkeitä asioita ylös muistilapulle.
⇒ I write down important things in general / some important things (not specified which, not necessarily all). This can sound more like a habitual or ongoing activity, or like you’re not committing to the idea that the whole relevant set is being written.

Both are grammatically correct; the choice depends on whether you’re talking about a specific, complete set or a more open, indefinite set.

Why is there no word for “I” in Kirjoitan tärkeät asiat ylös muistilapulle?

Finnish usually doesn’t need subject pronouns when the verb ending already shows the person:

kirjoittaa = “to write” (basic form)
kirjoitan = “I write / I am writing / I will write”

The -n ending marks first person singular, so the subject minä (“I”) is optional:

Kirjoitan tärkeät asiat ylös muistilapulle.
Minä kirjoitan tärkeät asiat ylös muistilapulle.

Both are correct; the version with minä often stresses the subject:

Minä kirjoitan tärkeät asiat ylös…
= “I write the important things down (not someone else).”

In neutral statements, Finnish prefers to omit the pronoun.

Is kirjoitan present or future tense? Could it mean “I will write the important things down”?

Finnish has one basic present tense form that covers:

Simple present: “I write the important things down.”
Progressive: “I am writing the important things down.”
Simple future (when context implies future): “I will write the important things down.”

So kirjoitan can mean any of these, depending on context. There is no separate grammatical future tense like English will write.

What case is muistilapulle, and what does that case mean?

Muistilapulle is in the allative case:

Basic form: muistilappu (“memo note, sticky note”)
Allative singular: muistilapulle (“onto a note / onto the memo note”)

The allative (-lle) usually expresses:

Movement onto a surface or to a recipient / goal:
- pöydälle = onto the table
- lapselle = to the child
- muistilapulle = onto a note

Here it indicates where the writing ends up: onto the note.

Why is it muistilapulle and not muistilappuun? Aren’t both something like “onto a note”?

Both are location/direction cases, but they differ slightly:

muistilapulle (allative) = onto the note, onto the surface
muistilappuun (illative) = into the note, into the inside of something

A note (a small piece of paper) is typically seen as a surface in Finnish, not as a container, so -lle is more natural:

Kirjoitan muistilapulle. = “I write (onto) a note.”

Muistilappuun would sound odd here, as if the note were a box or interior space. For surfaces like paper, board, walls, etc., Finnish tends to use -lle:

taululle = onto the board
paperille = onto the paper
lapulle / muistilapulle = onto the slip / note

Can the word order change, like Kirjoitan ylös tärkeät asiat muistilapulle or Tärkeät asiat kirjoitan ylös muistilapulle?

Yes, Finnish word order is flexible, and both of these are possible:

Kirjoitan tärkeät asiat ylös muistilapulle. (original)
– Neutral statement, focus towards the end (where/what you do with them).
Kirjoitan ylös tärkeät asiat muistilapulle.
– Emphasizes the verb phrase kirjoitan ylös as a unit (“I write down the important things on a note”). Still natural.
Tärkeät asiat kirjoitan ylös muistilapulle.
– Emphasizes tärkeät asiat (“The important things I write down on a note,” maybe contrasting with unimportant things that you don’t write).

The basic meaning stays the same, but moving elements changes the information focus and style.

How does tärkeät asiat work grammatically? Why does the adjective also change form?

In Finnish, adjectives agree with the nouns they modify in:

Number (singular/plural)
Case (nominative/partitive/etc.)

Here:

Noun: asia → plural nominative asiat
Adjective: tärkeä → plural nominative tärkeät

So you get tärkeät asiat = “(the) important things”.
Both words show:

plural: -t
nominative: the basic, unmarked form for a total object here.

If the noun were partitive plural asioita, the adjective would also switch to partitive plural tärkeitä asioita.

Is kirjoittaa ylös the only way to say “write down”? What about kirjoittaa muistiin?

There are several natural ways to say “write down / record” in Finnish:

kirjoittaa ylös
– Very common, informal, everyday speech: “to write down, jot down”.
kirjoittaa muistiin
– Slightly more “neutral” or a bit bookish/formal: literally “to write into memory,” also used a lot:
- Kirjoitan tämän muistiin. = “I’ll write this down / make a note of this.”
panna / laittaa muistiin
– More idiomatic: “to put down as a reminder, to note down.”

In your sentence, you could say:

Kirjoitan tärkeät asiat muistiin muistilapulle.
– Also correct, maybe a bit more formal-sounding, but very natural.

Could I replace muistilapulle with paperille? Is there any nuance difference?

Yes, you can say:

Kirjoitan tärkeät asiat ylös paperille.
= “I write the important things down on paper.”

Nuance:

muistilapulle:
– Specifically suggests a small note, memo, or sticky note. It feels like a quick reminder or list.
paperille:
– More general: “onto (a piece of) paper.” Could be a sheet, a notebook page, etc.

Both are correct; you just choose the one that best fits what you’re actually writing on.