Learn Hardcore Swedish: Hennes syster har motsatt smak och älskar röd klänning, gul kjol och grön kostym. - Her sister has the opposite taste and loves a red dress, a yellow skirt and a green suit.

Hennes syster = her sister (the “her” is some woman mentioned in the wider context)
Sin syster would mean her own sister, where “she” is also the subject of the clause.

In this sentence, hennes syster is the subject, so you cannot use sin in front of it. Sin must refer back to a subject that is already there, e.g.:

Hon älskar sin syster. – She loves her (own) sister.
Hennes syster älskar röd klänning. – Her sister loves red dresses. (the sister is the subject, and hennes refers to some other “she” in the context)

What does har motsatt smak literally mean, and is this a common expression?

Literally, har motsatt smak means “has opposite taste”.

ha … smak = “to have … taste” (in clothes, food, music, etc.)
motsatt = “opposite”

So Hennes syster har motsatt smak is like saying “Her sister’s taste is the opposite.” Yes, this is a natural and common way to express that two people like very different or opposite things, especially in fashion or preferences:

Vi har ganska olika smak. – We have quite different taste.
De har helt motsatt smak i musik. – They have completely opposite taste in music.

Why is there no en before the clothes, like en röd klänning?

Swedish can drop the indefinite article when you talk about things in a general, generic way – types of things, not specific items.

Hon älskar röd klänning.
= She loves red dresses / red dresses as a type.
Hon älskar en röd klänning.
= She loves a (particular) red dress.

In this sentence, the idea is “She loves red dresses, yellow skirts and green suits (in general)” – i.e. these are her preferred kinds of clothes, not three specific items. Therefore, no “en” is natural here.

You can say en röd klänning, en gul kjol och en grön kostym if you clearly mean three individual garments.

Why are the colour adjectives röd, gul, grön in their basic form and not röda, gula, gröna?

Swedish adjectives change depending on gender, number, and definiteness.

For indefinite singular common-gender (en-words), you use the base form of the adjective:

en röd klänning – a red dress
en gul kjol – a yellow skirt
en grön kostym – a green suit

Since klänning, kjol, kostym are all en-words, and we’re talking about them indefinitely and in the singular, the adjectives stay in their base form: röd, gul, grön.

You use -a (röda, gula, gröna) for:

Definite form (the …)
- den röda klänningen – the red dress
- den gröna kostymen – the green suit
All plurals (indefinite + definite)
- röda klänningar – red dresses
- de gröna kostymerna – the green suits

How would these colour phrases change if the nouns were neuter (ett-words)?

For indefinite singular neuter (ett-words), you add -t to most adjectives:

ett rött hus – a red house
ett grönt äpple – a green apple
ett gult rum – a yellow room

So if the clothing nouns were neuter (they are not, but as an example):

ett rött skärp – a red belt
ett grönt linne – a green tank top

Pattern:

en röd kjol → ett rött skärp
en grön kostym → ett grönt plagg

Why is it röd klänning and not klänning röd? Does Swedish normally put adjectives before nouns?

Yes, Swedish normally places adjectives before the noun, just like English:

röd klänning – red dress
gul kjol – yellow skirt
grön kostym – green suit

Putting the adjective after the noun is possible, but then it’s a different construction, often with är (“is”) or similar:

Klänningen är röd. – The dress is red.
Kjolen är gul. – The skirt is yellow.

So for direct noun phrases (a red dress / red dress), the standard word order is adjective + noun.

Is there any difference between motsatt smak and something like olika smak or annorlunda smak?

Yes, there is a nuance:

motsatt smak – opposite taste
Implies very strongly contrasting preferences, often almost the exact reverse.
olika smak – different taste
Neutral: they don’t like the same things, but not necessarily opposite.
annorlunda smak – a different / unusual taste
Often means “different from what is expected” or from my taste; can imply “unusual” or “quirky”.

In this sentence, motsatt smak emphasizes that her sister’s taste is sharply different, not just mildly different.

Could you also use tycker om instead of älskar here? What’s the difference?

Yes, grammatically you could say:

… och tycker om röd klänning, gul kjol och grön kostym.

The difference in meaning:

älskar = loves – strong liking
tycker om = likes – more neutral

In everyday speech, Swedes often use tycker om where English might say “like” and älskar where English uses “love”. This sentence uses älskar to stress that she really likes these types of clothes.

Why is there a comma only between röd klänning and gul kjol, and no comma before och?

Swedish punctuation in lists is similar to British English: you normally do not use a serial (Oxford) comma before och:

röd klänning, gul kjol och grön kostym
= red dress, yellow skirt and green suit

So:

commas between the first items,
no comma before och in a simple list.

What exactly does kostym mean in Swedish – is it like English “costume”?

Kostym in Swedish most commonly means “(business) suit”, especially:

a man’s suit (jacket + trousers), or
a woman’s matching suit (jacket + skirt/trousers).

It does not usually mean a fancy-dress or stage costume. For that, Swedish would more often use:

dräkt – outfit / costume (can be traditional dress, uniform, etc.)
maskeraddräkt – costume for a costume party

So in this sentence, grön kostym is best understood as “a green suit”, not “a green costume”.

How do you pronounce tricky words like kjol, röd, and grön?

Approximate pronunciation (Swedish varies a bit by region):

kjol (skirt) – IPA: /ɕuːl/
- kj here is the “sj-sound” (similar to a soft “sh” but further back in the mouth).
- The vowel o is like long oo in “shoe”.
röd (red) – IPA: /røːd/ (often /røː/ in casual speech)
- ö is like the vowel in French “bleu” or German “schön”: rounded “e” sound.
- The d can be quite soft or almost silent at the end.
grön (green) – IPA: /grøːn/
- Same ö sound as in röd.
- The r is often a tapped or rolled r, and n is fully pronounced.

A rough English approximation:

kjol ≈ “shool” (but with the sound a bit further back)
röd ≈ “rurd” (short, with a rounded “e”)
grön ≈ “grurn” (again with that rounded “e”)