Learn Hardcore Finnish: Tämä arvo on minulle tärkeä.

tämä = this (demonstrative pronoun, nominative singular)
arvo = value (here in the sense of a moral principle or something you consider important; it can also mean worth, price, numerical value, but context decides)
on = is (3rd person singular of olla, to be)
minulle = to me / for me (allative case of minä, I)
tärkeä = important (adjective, here in its basic nominative form, used as a predicate)

So literally: This value is to-me important.

Why is it tämä arvo and not tämän arvo? Aren’t both forms of tämä?

Yes, both are forms of tämä, but they are different cases:

tämä = nominative (basic form, used for the subject)
tämän = genitive (often used for possession or as an object form)

In Tämä arvo on minulle tärkeä:

tämä arvo is the subject of the sentence, so it must be in the nominative.
Therefore tämä (not tämän) is used.

If you said:

Tämän arvon opin lapsena. = I learned this value as a child.

Here tämän arvon is an object, so tämän (genitive) + arvon (genitive) is correct.

What case is minulle, and what does that case generally mean?

Minulle is in the allative case.

Base: minä = I
Allative: minulle = to me, for me, onto me

The allative (-lle) case typically expresses:

direction towards something:
- pöytä → pöydälle = onto the table
a recipient or beneficiary:
- Anna se minulle. = Give it to me.
- Tämä kirja on sinulle. = This book is for you.

In Tämä arvo on minulle tärkeä, minulle shows for whom this value is important → to me / for me.

Why is it minulle and not just minä or minun?

Because Finnish uses a case ending to show the role of me in the sentence.

minä = I (nominative, used as subject)
- Minä olen väsynyt. = I am tired.
minun = my (genitive, possession)
- Minun arvoni = my value
minulle = to/for me (allative, recipient/beneficiary)
- Tämä arvo on minulle tärkeä. = This value is important to me.

In this sentence, we need the idea “important to me”, not “I” or “my”, so minulle (allative) is the correct choice.

What form is tärkeä, and why doesn’t it have any ending here?

Tärkeä is an adjective in its basic (nominative singular) form.

In sentences with “X is Y” where Y is an adjective describing the subject, Finnish usually uses the nominative form of the adjective:

Auto on uusi. = The car is new.
Opettaja on ystävällinen. = The teacher is friendly.
Tämä arvo on tärkeä. = This value is important.

So tärkeä is the normal predicate form here.

If the subject is plural, the adjective often appears in partitive plural:

Nämä arvot ovat minulle tärkeitä. = These values are important to me.

Does tärkeä have to agree with arvo in number and case like English adjectives don’t?

Finnish adjectives do show agreement, but not always in the way English learners expect.

In this kind of “X is Y (adjective)” structure:

Singular subject: adjective in nominative singular
- Tämä arvo on tärkeä.
Plural subject: adjective often in partitive plural in this meaning of “is/are important”
- Nämä arvot ovat tärkeitä.

In other contexts (not just with olla), adjectives match the noun’s case and number:

tärkeä arvo (nom. sg.) = an important value
tärkeän arvon (gen. sg.) = of an important value
tärkeää arvoa (part. sg.)
tärkeitä arvoja (part. pl.)

So yes, tärkeä behaves like other Finnish adjectives and agrees with arvo, but in this specific sentence type its form is just the basic nominative.

Can I change the word order, e.g. say Tämä arvo on tärkeä minulle instead?

Yes, you can. Both are grammatically correct:

Tämä arvo on minulle tärkeä.
Tämä arvo on tärkeä minulle.

The difference is mainly emphasis and rhythm, not meaning.

Roughly:

... on minulle tärkeä slightly emphasizes “to me” as a closer link to tärkeä.
... on tärkeä minulle can sound a bit more neutral or put a slight emphasis at the end.

Finnish word order is fairly flexible, but it’s not completely free: changes often affect what is being highlighted or contrasted. Here, both orders are very natural.

Why is the verb on needed? Sometimes I see Finnish sentences without on.

In this sentence, on (the verb olla, to be) is required.

Tämä arvo on minulle tärkeä. = This value is important to me.

You cannot say:

✗ Tämä arvo minulle tärkeä. (ungrammatical)

The copula olla is normally needed in “X is Y” sentences.

Where you might see no clear on is in:

Headline-like or very elliptical expressions
Some existential constructions where on may be omitted in certain colloquial styles
Commands or short notes like Lippu voimassa 24h (Ticket valid 24h), which are more like reduced structures

But for a normal full sentence like you’re learning, keep on.

What is the difference between “Tämä arvo on minulle tärkeä” and “Tämä arvo on minusta tärkeä”?

Both are correct but express slightly different nuances.

Tämä arvo on minulle tärkeä.
- Literally: This value is important *to me.*
- Means: This value matters to me personally; I care about it; it is part of my values.
Tämä arvo on minusta tärkeä.
- Literally: This value is important *in my opinion / as I see it.*
- minusta (elative case) here means “in my opinion”.
- This focuses more on your judgment: you think the value is important, maybe in general.

So:

minulle tärkeä = emotionally, personally important to me
minusta tärkeä = I think it’s important (opinion)

Could I say “Tämä arvo on tärkeä mulle” instead of minulle?

Yes, mulle is the colloquial spoken form of minulle.

minulle = standard written Finnish
mulle = everyday spoken Finnish / informal writing (messages, chats, etc.)

So:

Tämä arvo on mulle tärkeä.

is very natural in spoken Finnish but is usually avoided in formal writing.

How would I say the same thing in the plural: “These values are important to me”?

You change both the noun and the verb to plural, and usually use the partitive plural for tärkeä:

Nämä arvot ovat minulle tärkeitä.
- nämä = these
- arvot = values (nominative plural of arvo)
- ovat = are (3rd person plural of olla)
- minulle = to me
- tärkeitä = important (partitive plural of tärkeä)

So the full plural version is: Nämä arvot ovat minulle tärkeitä.

How do tämä, tuo, and se differ? Could I say Tuo arvo on minulle tärkeä or Se arvo on minulle tärkeä?

All three are demonstrative words, but they differ mainly in distance and context.

tämä = this (near the speaker)
tuo = that (a bit farther away, but visible / in the shared space)
se = that/it (more distant, or already known/mentioned in context, often like English it)

In your sentence:

Tämä arvo on minulle tärkeä.
- This value (here / that we are focusing on) is important to me.

You could say:

Tuo arvo on minulle tärkeä.
- That value (over there / that one you mentioned) is important to me.
Se arvo on minulle tärkeä.
- That value / that one is important to me. (often referring to something already known from context, sometimes sounds a bit redundant; usually you’d just say Se on minulle tärkeä. = It is important to me.)

So yes, they are possible, but tämä points clearly to “this (specific) value here / the one we are talking about”.

Is there anything special about the pronunciation of Tämä arvo on minulle tärkeä that I should know?

A few tips:

ä is like in cat, but longer and clearer: tämä, tärkeä, minulle.
Double consonants are held longer than single ones (not emphasized louder, but literally longer in time). Here you don’t have double consonants, but remember this rule in general.
Word stress is always on the first syllable of each word:
- TÄ-mä AR-vo on MI-nul-le TÄR-ke-ä
In natural speech, words connect smoothly, so you’ll often hear:
- Tämä arvo on minulle tärkeä almost as one flow, with no strong breaks between words.

Practicing saying it slowly with correct ä sounds and initial stress will help you sound much more natural.