Tämä satu on lyhyt, mutta todella kaunis.

Yes. Tämä means this.

In this sentence, tämä is pointing to satu: this story / this fairy tale.

A few useful notes:

• tämä is the singular form: this
• the plural is nämä: these
• Finnish does not mark gender here, so tämä works regardless of whether English would say he, she, or it later

In Tämä satu, both words are in the basic subject form, called the nominative.

Satu usually means fairy tale, folk tale, or simply story/tale, depending on context.

So the word can feel a little more specific than the English word story. It often suggests something fictional, imaginative, or traditional.

For example:

• lastensatu = children’s fairy tale
• iltasatu = bedtime story

In your sentence, satu is the thing being described as short and really beautiful.

Because Finnish normally does not use articles.

English:

• a story
• the story

Finnish often just says:

• satu

So Tämä satu already clearly means this story / this fairy tale, and Finnish does not need a separate word for the.

This is very normal in Finnish and is one of the first big differences English speakers notice.

On is the third person singular present tense of olla, which means to be.

So:

• olen = I am
• olet = you are
• on = he/she/it is, or a singular noun is
• olemme = we are
• olette = you are
• ovat = they are

Since Tämä satu is a singular subject, Finnish uses on:

• Tämä satu on lyhyt. = This story is short.

A useful thing to remember: Finnish uses the same on for he, she, and it.

They are in their basic dictionary form here because they are predicate adjectives: adjectives that come after to be and describe the subject.

So in:

• Tämä satu on lyhyt.
• Tämä satu on kaunis.

the adjectives lyhyt and kaunis describe satu after the verb on.

For a singular subject like this, that is completely normal.

A helpful comparison:

• lyhyt satu = a short story
• satu on lyhyt = the story is short

In both examples, lyhyt stays in the same basic form because everything is singular and nominative here.

Good question. Yes, -t often marks the plural on nouns, but in lyhyt the -t is just part of the word itself.

So lyhyt is simply the normal singular dictionary form of the adjective short.

It is not plural here.

This is important because Finnish words can end in -t for different reasons:

• sometimes it is a plural ending
• sometimes it is just part of the basic form of the word

So in this sentence:

• satu is singular
• lyhyt is also singular

Todella means really, truly, or sometimes very, depending on context.

Here it works as an intensifier: it strengthens kaunis.

So:

• kaunis = beautiful
• todella kaunis = really beautiful

It comes before the adjective because it is modifying that adjective, just like in English:

• really beautiful
• very beautiful

Other common intensifiers in Finnish include:

• hyvin = very / well
• tosi = really / very (more informal)
• erittäin = very / extremely

Because mutta means but, and Finnish commonly uses a comma before it when joining contrasting parts of a sentence.

So:

• Tämä satu on lyhyt, mutta todella kaunis.

The comma helps show the contrast:

• short
• but really beautiful

This is quite similar to English punctuation in many cases.

Yes, something is being left out, but it is completely natural.

The full idea is basically:

• Tämä satu on lyhyt, mutta se on todella kaunis.
• This story is short, but it is really beautiful.

In Finnish, if something is obvious from context, it is often omitted. Here the subject and verb in the second part are easy to understand, so the shorter version sounds natural:

• Tämä satu on lyhyt, mutta todella kaunis.

So the sentence is not ungrammatical; it is just more compact.

Yes, double letters matter a lot in Finnish, and y is also important.

1. The vowel y

Finnish y does not sound like English y in yes.

It is a front rounded vowel, similar to:

• German ü
• French u

English speakers often need practice with it.

In lyhyt, both y sounds are that Finnish y vowel.

2. Double letters

Finnish double letters are pronounced longer than single ones, and the difference can change meaning.

In this sentence:

• mutta has a double tt
• todella has a double ll

That means you should hold those consonants a little longer:

• mut-ta
• to-del-la

This is not just spelling decoration; it is a real pronunciation difference in Finnish.