Learn Hardcore Finnish: En pidä ruuhkaisesta tavaratalosta, joten teen lahjalistan kotona rauhassa. - I don’t like the crowded department store, so I make a gift list at home in peace.

The negative verb (en, et, ei, emme, ette, eivät) carries the person.
The main verb goes into a personless “connegative” form, which for this verb is pidä (same for all persons in the negative).

So:

Minä pidän = I like
En pidä = I don’t like (literally “I-not like”)

You can say minä en pidä; adding minä just adds emphasis (“I don’t like…”).
But *en pidän is always wrong: with a negative verb, you must use pidä, not pidän.

Why is ruuhkaisesta tavaratalosta in the -sta form? I expected something like a basic form for “crowded department store”.

The verb pitää in the sense of “to like” normally takes its object in the elative case (-sta / -stä):

pitää jostakin = to like something (literally “to like from something”)

So:

En pidä ruuhkaisesta tavaratalosta.
= I don’t like the crowded department store.

Both the adjective ruuhkainen and the noun tavaratalo must agree in case:

base forms: ruuhkainen tavaratalo
elative singular: ruuhkaisesta tavaratalosta

That’s why both words get -sta.

What exactly does ruuhkaisesta mean and how is it formed?

Ruuhkaisesta comes from:

noun ruuhka = a traffic jam / crowd / rush
adjective ruuhkainen = crowded, jammed, busy (with people)

Then we put ruuhkainen into the elative singular to match pitää jostakin:

ruuhkainen → stem ruuhkaise-
- -sta → ruuhkaisesta

So literally: “from (a) crowded …” → “(about) a crowded …”
In context: ruuhkaisesta tavaratalosta = from a crowded department store → “a crowded department store” after like/dislike.

Why is tavaratalosta also in the -sta form? Couldn’t just the adjective carry the ending?

In Finnish, adjectives usually agree in case and number with the noun they describe.

Phrase:

base: ruuhkainen tavaratalo (crowded department store)
elative singular for both:
- ruuhkaisesta (adjective)
- tavaratalosta (noun)

You can’t normally put the ending only on the adjective:

*ruuhkaisesta tavaratalo – incorrect
ruuhkaisesta tavaratalosta – correct

So the whole noun phrase “crowded department store” is in the elative because pitää requires jostakin.

Could I say En pidä ruuhkaisista tavarataloista instead? What’s the difference?

Yes, that is correct and actually a bit more natural for a general statement.

En pidä ruuhkaisesta tavaratalosta.
= I don’t like the crowded department store (more specific: a particular one, or one situation).
En pidä ruuhkaisista tavarataloista.
= I don’t like crowded department stores (in general).

So the difference is singular specific vs. plural general.
English often uses the plural for general dislikes, and Finnish can mirror that with the plural elative -sta → -sta / -sta → -sta? (More precisely: ruuhkaisista tavarataloista).

What is the function of joten here? Could I use niin or siksi instead?

Joten is a conjunction meaning “so / therefore”, introducing a result:

En pidä ruuhkaisesta tavaratalosta, joten teen lahjalistan kotona rauhassa.
= I don’t like the crowded department store, so I make the gift list at home in peace.

Alternatives:

… , siksi teen lahjalistan …
siksi = “for that reason / that’s why” (adverb, feels a bit more formal/explicit).
niin että can mean “so that”, but plain niin alone does not work as the same kind of conjunction here.

So the closest direct replacement is siksi, but joten is the natural, neutral choice for “so / therefore” between two clauses.

Why is lahjalistan ending in -n?

Lahjalistan is the object of teen (“I make”).

verb: tehdä = to make, to do
teen = I make / I do
lahjalista = gift list

In this sentence, you make one complete gift list, so it’s a total object.
For a singular total object, the form is often genitive singular, which ends in -n:

base: lahjalista
genitive / total object: lahjalistan

Compare:

Teen lahjalistan. = I make the/a whole gift list.
Teen lahjalistaa. = I’m (in the process of) making a gift list / working on it (partitive, incomplete/ongoing).

Is kotona some special irregular form? How is it different from kotiin or kodissa?

Kotona is the usual word for “at home”.

Forms from koti (home):

kotiin = (to) home, direction towards home (illative)
- Menen kotiin. = I’m going home.
kotona = at home, location at home (adessive/locative-like, used idiomatically)
- Olen kotona. = I am at home.
kotoa = from home (elative-like)
- Lähden kotoa. = I leave (from) home.

You will occasionally see kodissa, kodista, kodin, etc., in other meanings (house/household), but for the everyday sense of “home” as a place where you live, kotona is the standard form for “at home”.

What does rauhassa literally mean, and how is it used?

Rauhassa comes from:

noun rauha = peace
inessive singular rauhassa = “in peace”

It’s used adverbially to mean:

in peace and quiet
calmly, without disturbance

Examples:

Haluan juoda kahvini rauhassa.
I want to drink my coffee in peace.
Teen lahjalistan kotona rauhassa.
I make the gift list at home in peace and quiet / calmly.

So it literally means “in peace”, but functions like the adverb “peacefully”.

Can I change the word order, for example: Teen kotona rauhassa lahjalistan? Does it change the meaning?

Yes, you can change the word order; Finnish is quite flexible.
All of these are grammatically correct:

Teen lahjalistan kotona rauhassa.
Teen kotona rauhassa lahjalistan.
Kotona teen lahjalistan rauhassa.

The basic meaning stays the same: you make the gift list at home in peace.

Differences are mostly about rhythm and emphasis:

Starting with Kotona emphasises the place more: “At home, I make the gift list in peace (as opposed to somewhere else).”
Putting lahjalistan first after teen is very neutral and natural.

For a learner, the original order is a good default; later you can play with word order for emphasis.

Is there a difference between En pidä ruuhkaisesta tavaratalosta and something stronger like Vihaan ruuhkaisia tavarataloja?

Yes, there’s a clear difference in strength of feeling:

En pidä ruuhkaisesta tavaratalosta.
= I don’t like / I dislike the crowded department store.
→ A mild/neutral negative opinion.
Vihaan ruuhkaisia tavarataloja.
= I hate crowded department stores.
→ Much stronger emotion.

Grammar:

pitää jostakin = to like something (object in elative)
vihata jotakuta / jotakin = to hate someone/something (object usually in the partitive in this kind of general statement)

So the original sentence expresses a mild dislike, not extreme hatred.

Why is there a comma before joten? Is that always required?

Yes, in standard written Finnish, you normally put a comma before coordinating conjunctions like joten, mutta, vaan, ja when they join two full clauses (each with its own verb):

En pidä ruuhkaisesta tavaratalosta, joten teen lahjalistan kotona rauhassa.
- clause 1: En pidä …
- clause 2: teen lahjalistan …
- joined by joten → comma before it.

So here the comma is expected and correct.