Learn Hardcore Finnish: Tämä laulu on kaunis.

Tämä laulu can mean this song, not this a song or this the song.
The demonstrative tämä already makes the noun specific, similar to this or sometimes this particular.

If you wanted just the song is beautiful (without the this idea), you would normally say:

Laulu on kaunis. = The song is beautiful. (or A song is beautiful, context decides)

Why is it Tämä laulu and not something like Tämän laulu?

Tämä is the basic, dictionary form (nominative singular) of the demonstrative this used as the subject:

Tämä laulu = this song (subject of the sentence)

Tämän is a different case (genitive), usually showing possession:

tämän laulun sanat = the lyrics of this song (literally: this’s song’s lyrics)

In Tämä laulu on kaunis, tämä laulu is simply the subject, so both words stay in the nominative case.

Why are laulu and kaunis in the same form (both basic form, no endings)?

When you have a sentence with to be and a singular subject, the subject and the describing word (predicative) are usually both in the nominative singular:

Tämä laulu (subject, nominative singular)
on
kaunis (predicative adjective, nominative singular)

This matches English: This song (subject) is beautiful (adjective).

If the subject is plural, the adjective usually becomes plural nominative too:

Nämä laulut ovat kauniit. = These songs are beautiful.
- Nämä laulut = these songs (plural)
- kauniit = beautiful (plural nominative form of kaunis)

Could I say Laulu on kaunis instead? Does the meaning change?

Yes, you can say:

Laulu on kaunis.

This usually means The song is beautiful or A song is beautiful, depending on context. The difference:

Tämä laulu on kaunis. = This song is beautiful (you are clearly pointing to or talking about a specific song, this one here)
Laulu on kaunis. = more general or context‑dependent; it might be:
- a specific known song (the one you’ve been talking about), or
- a general statement about “song” or “singing” being beautiful, depending on context.

So tämä adds the clear this meaning.

What is on exactly, and how does it change with different subjects?

On is the 3rd person singular form of the verb olla (to be).

Present tense forms of olla:

minä olen = I am
sinä olet = you (singular) are
hän on = he/she is
se on = it is (for things/animals in speech)
me olemme = we are
te olette = you (plural / polite) are
he ovat = they (people) are
ne ovat = they (things/animals in speech) are

So in Tämä laulu on kaunis, laulu is third person singular, so you use on.

How would I say This song is not beautiful?

Finnish uses a special negative verb ei. To say is not, you use ei plus the verb olla in a short form:

Tämä laulu ei ole kaunis. = This song is not beautiful.

Structure:

Tämä laulu = this song
ei = not (negative verb, 3rd person singular here)
ole = base form of olla used with ei
kaunis = beautiful

So the positive on becomes ei ole in the negative.

How do I pronounce Tämä laulu on kaunis?

Approximate pronunciation (using English-like spelling):

Tämä ≈ “TA-ma”
- ä = like a in cat
laulu ≈ “LAU-lu”
- au is a diphthong, like ow in now, but shorter and smoother
on ≈ “on” (like English on, but shorter)
kaunis ≈ “KOW-nis”
- kau like cow in English but a bit shorter
- i like ee in see, but short
- s always like s in see, never like z

Key tips:

Every written vowel is pronounced.
Stress is always on the first syllable: TÄ-mä LAU-lu on KAU-nis.

What’s the difference between tämä, tuo, and se?

They all can translate as this/that/it, but there are distance and usage nuances:

tämä = this (near the speaker)
- Tämä laulu on kaunis. = This song (here/just mentioned) is beautiful.
tuo = that (a bit further away)
- Tuo laulu on kaunis. = That song (over there) is beautiful.
se = it / that (often something already known from context, not about physical distance)
- Se laulu on kaunis. = That song / It (the song we were just talking about) is beautiful.

In natural speech, se is extremely common for previously mentioned things.

Does the adjective kaunis have to “agree” with laulu in number and case?

Yes. In Finnish, adjectives generally agree with the noun in:

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

In your sentence, subject and adjective are both singular nominative:

Tämä laulu on kaunis.

Other examples:

Kaunis laulu on tämä. = A beautiful song is this (one).
- kaunis laulu: both singular nominative
Nämä kauniit laulut ovat kuuluisia. = These beautiful songs are famous.
- Nämä (these), kauniit (beautiful, plural nominative), laulut (songs, plural nominative)

How would I say These songs are beautiful?

Two common options, with a subtle nuance:

Nämä laulut ovat kauniit.
- Nominative plural predicate (kauniit)
- Often feels a bit more “complete group”, “these specific songs are beautiful (as a whole).”
Nämä laulut ovat kauniita.
- Partitive plural predicate (kauniita)
- Often sounds a bit more descriptive, like you’re talking about their quality in a looser, less “all‑of‑them-as-a-whole” way.

Both are grammatically correct; the difference is mostly nuance and style. With a singular like Tämä laulu on kaunis, you just use kaunis (nominative singular).

Is laulu the only word for song, or could I use something else?

Laulu is the most basic word for song, but there are others:

kappale (often shortened biisi in colloquial speech)
- Tämä kappale on kaunis. = This track/song is beautiful.
laulu can also sometimes mean “singing” or a particular “song/chant.”

In your sentence, Tämä laulu on kaunis is perfectly natural and neutral. Tämä kappale on kaunis is also common when talking about recorded music or a specific piece on an album or playlist.