Learn Hardcore Finnish: Minun makuuhuoneeni on pieni mutta rauhallinen.

So minun makuuhuoneeni literally has both a possessive pronoun and a possessive suffix. In standard written Finnish, this is perfectly normal and quite common.

You have three main options:

makuuhuoneeni on pieni… – fully correct, often used in writing.
minun makuuhuoneeni on pieni… – also fully correct; the pronoun can add clarity or emphasis.
mun makuuhuone on pieni… – very common in spoken language (colloquial), but not “standard” written Finnish.

What is usually avoided in formal writing is minun makuuhuone (without the suffix) – that sounds colloquial or incomplete in standard language.

Can I leave out Minun and just say Makuuhuoneeni on pieni mutta rauhallinen?

Yes.

Makuuhuoneeni on pieni mutta rauhallinen is completely correct and actually a bit more typical in neutral written Finnish than Minun makuuhuoneeni….

With Minun: you slightly emphasize whose bedroom it is, or you make it explicit when context might be unclear.
Without Minun: you simply state “my bedroom is small but quiet”, with the possession already clear from -ni.

So both are fine; leaving minun out is often the default if context is clear.

What are the parts of makuuhuoneeni and what do they each mean?

makuuhuoneeni can be broken down like this:

makuu = “sleeping” (from nukkua, “to sleep”; makuu is a noun related to lying/sleeping)
huone = “room”
makuuhuone = “bedroom” (literally “sleeping-room”)
makuuhuone
- -ni → makuuhuoneeni = “my bedroom”

So the structure is: makuu + huone + -ni → makuuhuoneeni.

How do you pronounce the whole sentence?

The sentence:

Minun makuuhuoneeni on pieni mutta rauhallinen.

Basic pronunciation tips:

Stress is always on the first syllable of each word.
Double vowels (uu, oo, ee, aa) are long.
Double consonants (tt, ll) are also long.

Approximate syllable division and stress (stressed syllables in CAPS):

MI-nun
MA-kuu-HUO-nee-ni
on
PIE-ni
MUT-ta
RAU-hal-li-nen

A few specific points:

uu in makuuhuoneeni is a long “oo” sound.
uo in huo (of huone) is a diphthong, similar to English “uo” in “quota”, but smoother.
rau in rauha- is like “row” (as in “row a boat”) but with a rolled/flapped r.
ll in rauhallinen is held slightly longer than a single l.

Why is the verb on and not olen?

Because the subject of the sentence is makuuhuoneeni (“my bedroom”), which is 3rd person singular (“it”), not “I”.

The verb olla (“to be”) conjugates, for example:

minä olen = I am
sinä olet = you are (singular)
hän on = he/she is
se on = it is

Here, makuuhuoneeni (se) behaves like “it”, so you use on:

Makuuhuoneeni on pieni… = “My bedroom is small…”

Why is there no word for “it” in the Finnish sentence, like in English “It is small”?

In Finnish you normally name the thing directly instead of using “it” if you’re introducing or describing it:

Makuuhuoneeni on pieni. = “My bedroom is small.”

You would use se (“it/that”) mainly when you are referring back to something that is already known in the context:

Makuuhuoneeni on pieni. Se on kuitenkin rauhallinen.
“My bedroom is small. It is, however, quiet.”

So in your original sentence, makuuhuoneeni itself is the subject, so there is no need for a separate “it”.

Why are pieni and rauhallinen in this basic form? Shouldn’t they change to match makuuhuoneeni?

They do match it, just in a way that looks “basic” to an English speaker.

In Finnish, adjectives that describe the subject in sentences with olla (“to be”) usually appear in the nominative case and agree in number and case with the subject:

(Yksi) makuuhuoneeni on pieni. – “My bedroom is small.”
- subject: makuuhuoneeni (singular, nominative)
- adjective: pieni (singular, nominative)

If the subject were plural, the adjective would also be plural:

Makuuhuoneeni ovat pienet. – “My bedrooms are small.”
- subject: makuuhuoneeni (plural, nominative)
- adjective: pienet (plural nominative)

So pieni and rauhallinen are in the correct “basic” / nominative form, agreeing with a singular subject in the nominative.

What is the nuance of rauhallinen? Is it the same as hiljainen (“quiet”)?

They’re related but not identical:

rauhallinen
- comes from rauha = “peace”
- means “peaceful, calm, unhurried, tranquil”
- can include “quiet”, but also the feeling of calmness
- e.g. rauhallinen huone / elämä / tunnelma = a peaceful room / life / atmosphere
hiljainen
- focuses more on low noise level: “quiet, silent”
- e.g. hiljainen katu = a quiet street (not much noise)

For a bedroom, both rauhallinen makuuhuone and hiljainen makuuhuone are natural, but rauhallinen hints more at an overall peaceful environment, not just lack of sound.

What exactly does mutta mean here, and how is it different from vaan?

mutta is the general word for “but” expressing contrast:

Makuuhuoneeni on pieni mutta rauhallinen.
“My bedroom is small but quiet.”

vaan is another word often translated as “but”, but it is mostly used:

after a negation, in the sense of “but rather / but instead”

Examples:

Se ei ole iso, vaan pieni.
“It is not big, but rather small.”
Haluan nukkua, en työskennellä, vaan levätä.
“I want to sleep, not work, but (rather) rest.”

In your sentence there’s no negation and no “instead of” idea, just a contrast, so mutta is the correct choice.

Why is there no comma before mutta in this sentence?

In Finnish, you usually put a comma before mutta when it connects two clauses with their own verbs:

Makuuhuoneeni on pieni, mutta se on rauhallinen.
- clause 1: Makuuhuoneeni on pieni
- clause 2: se on rauhallinen

In your sentence, there is only one verb (on). mutta links two adjectives (pieni and rauhallinen) that belong to the same clause:

Makuuhuoneeni on pieni mutta rauhallinen.

Because those adjectives are just parts of one clause, no comma is used.

Can I change the word order, for example Makuuhuoneeni on rauhallinen mutta pieni? Does that change the meaning?

Yes, you can say:

Makuuhuoneeni on rauhallinen mutta pieni.

It is grammatically correct. Both orders mean essentially:

“My bedroom is small but quiet.”

The difference is mostly in emphasis and what you present as more “expected” vs “surprising”:

pieni mutta rauhallinen
→ feels like: “It’s (unfortunately) small, but (at least) it’s quiet.”
rauhallinen mutta pieni
→ feels like: “It’s (nice and) quiet, but (the downside is) it’s small.”

So the nuance changes a little, but the basic facts are the same.

How would I say a similar sentence with other possessive pronouns, like “our bedroom is small but quiet”?

Using the same structure:

Meidän makuuhuoneemme on pieni mutta rauhallinen.
“Our bedroom is small but quiet.”

A few other persons:

Sinun makuuhuoneesi on pieni mutta rauhallinen. – Your (sg) bedroom…
Hänen makuuhuoneensa on pieni mutta rauhallinen. – His/her bedroom…
Heidän makuuhuoneensa on pieni mutta rauhallinen. – Their bedroom…

Notice:

The possessive suffix changes: -ni (my), -si (your), -mme (our), -nne (your plural), -nsa / -nsä (his/her/their).
The pronoun (minun, sinun, meidän, heidän…) is optional in many contexts, just like with minun.

Why is Minun in that -n form and not just minä?

Minun is the genitive form of minä (“I”):

minä = I (nominative)
minun = my (genitive, used for possession)

In Finnish, when you indicate possession using a pronoun before a noun, that pronoun is normally in the genitive:

minun auto / autoni = my car
sinun kirja / kirjasi = your book
meidän koti / kotimme = our home

In standard language you typically combine:

genitive pronoun + possessed noun with possessive suffix

as in Minun makuuhuoneeni.