Learn Hardcore Finnish: Joululomalla kaupunki hiljentyy, ja tavalliset kadun äänet muuttuvat pehmeämmiksi. - During the Christmas holiday the city quiets down, and the usual street sounds become softer.

Time expression: Joululomalla = during the Christmas holiday / at Christmas break
The adessive is very often used for “at / during [time]”:
- kesällä = in summer
- yöllä = at night
- viikonloppuna (essive here, but same idea: point of time)

So Joululomalla kaupunki hiljentyy = During the Christmas holiday, the city grows quiet.

Why is the verb hiljentyy used instead of something like on hiljainen?

hiljainen = quiet (adjective)
on hiljainen = is quiet (describes a state)
hiljentyy = becomes quiet / grows quiet (describes a change)

hiljentyy is the intransitive / “middle” form of hiljentää (to make something quieter).

So:

Kaupunki on hiljainen. = The city is quiet. (state)
Kaupunki hiljentyy. = The city becomes quiet / settles down. (process of becoming quieter)

In the sentence, we want to express what happens during the Christmas holiday, so the change-verb hiljentyy is more natural.

What is the function of the comma before ja in kaupunki hiljentyy, ja tavalliset kadun äänet…? In English we often don’t use it.

In Finnish, a comma is usually placed between two independent clauses, even when they are joined by ja (= and).

Here we have:

Kaupunki hiljentyy.
Tavalliset kadun äänet muuttuvat pehmeämmiksi.

Each has its own subject and verb, so they are separate clauses. Finnish punctuation rules normally require a comma:

Kaupunki hiljentyy, ja tavalliset kadun äänet muuttuvat pehmeämmiksi.

In English you might write this without a comma, but in Finnish the comma here is standard.

Why is it tavalliset kadun äänet and not tavalliset katu äänet or tavalliset kadut äänet?

Breakdown:

tavalliset = ordinary / usual (plural nominative, agreeing with äänet)
kadun = of the street (singular genitive of katu)
äänet = sounds (plural subject)

So kadun äänet means the sounds of the street, and tavalliset kadun äänet = the usual sounds of the street.

Why genitive?

Finnish typically uses genitive + noun to express “X of Y”:
- talon katto = the roof of the house
- kaupungin valot = the lights of the city
- kadun äänet = the sounds of the street

So katu must be in genitive (kadun) to show possession/association with äänet.

Could we also say kadun tavalliset äänet? Would that change the meaning?

Yes, kadun tavalliset äänet is also correct and natural.

Subtle difference in emphasis:

tavalliset kadun äänet – slightly more focus on tavalliset (ordinary/usual), then of the street as specification.
kadun tavalliset äänet – starts by anchoring to kadun (of the street), then specifies that these sounds are the usual ones.

Meaning-wise, both are the usual sounds of the street. Word order often shifts focus more than basic meaning in Finnish.

What form is pehmeämmiksi, and why isn’t it just pehmeämmät?

pehmeämmiksi is:

Comparative: pehmeä → pehmeämpi (soft → softer)
Plural stem: pehmeämmi-
Translative plural ending -ksi → pehmeämmiksi

So grammatically: comparative + plural + translative.

Why translative (-ksi)?

With verbs of change like muuttua (to become / to turn into), Finnish uses the translative case for the new state:
- Vesi jäätyy jääksi. = The water freezes into ice.
- Hän tuli vihaiseksi. = He / she became angry.
- Äänet muuttuvat pehmeämmiksi. = The sounds become softer.

pehmeämmät (nominative plural) would just describe a state:
Äänet ovat pehmeämmät. = The sounds are softer.
But muuttuvat pehmeämmiksi emphasizes the process of becoming softer.

How is muuttuvat pehmeämmiksi different from saying ovat pehmeämpiä?

muuttuvat pehmeämmiksi:
- Uses muuttua (to change, to become).
- Translative case (pehmeämmiksi) shows the resulting state.
- Focus: a change over time → they become softer.
ovat pehmeämpiä:
- Uses olla (to be).
- pehmeämpiä = comparative plural partitive (describing a quality).
- Focus: current state → they are softer (than something else).

In this sentence, the idea is that during the Christmas holiday, the sounds change, so muuttuvat pehmeämmiksi is the natural choice.

Why are tavalliset and äänet in plural, but kaupunki is singular? How does agreement work here?

Agreement rules:

Adjectives agree in number and case with the noun they modify:
- tavalliset äänet → both plural nominative
The verbs agree with the subject in number:
- kaupunki hiljentyy → singular verb, singular subject
- äänet muuttuvat → plural verb, plural subject

The sentence has two different subjects:

kaupunki (the city) → singular
tavalliset kadun äänet (the usual sounds of the street) → plural

So:

kaupunki hiljentyy (the city grows quiet)
tavalliset kadun äänet muuttuvat pehmeämmiksi (the usual street sounds become softer)

Is there a reason the sentence starts with Joululomalla instead of Kaupunki hiljentyy joululomalla?

Both are correct:

Joululomalla kaupunki hiljentyy…
Kaupunki hiljentyy joululomalla…

Starting with Joululomalla:

Puts time in focus: As for the Christmas holiday…
Very typical in Finnish: time or place adverbials often come first.

Starting with Kaupunki:

Focuses first on the city, then adds when it happens.

The meaning is essentially the same; the difference is in emphasis and flow, not in grammar correctness.

How do you pronounce hiljentyy and pehmeämmiksi? Any pitfalls for an English speaker?

hiljentyy:

Syllables: hil-jen-tyy
h as in house
i as in machine
j like English y in yes
tyy: t is dental, y is a front rounded vowel (like French u in tu or German ü)

So roughly: HIL-yen-tyü (with a long yy sound).

pehmeämmiksi:

Syllables: peh-me-äm-mik-si
peh: like peh in peck, but e is pure
ä: front vowel (like a in cat, but tenser and longer when doubled)
mm: double m, hold it slightly longer
ki: kee with a short i
si: see with a short i

The main pitfalls:

Pronouncing y like English y – it’s actually a vowel.
Not holding long sounds (like yy or mm) long enough; length is meaningful in Finnish.