Learn Hardcore Icelandic: Listasafnið er skemmtilegra en mörg önnur söfn. - The art museum is more fun than many other museums.

In Icelandic, compounds are normally written as a single word, and the definite article is also attached to the end of the noun rather than written as a separate word, so you get Listasafnið, not Lista safn ið or similar.

Why does Listasafnið end in -ið and not -inn, which I often see as “the”?

The form of the suffixed definite article depends on gender:

Masculine nominative singular: -inn (for example stóllinn – the chair)
Feminine nominative singular: -in (for example bókin – the book)
Neuter nominative singular: -ið (for example húsið – the house)

The noun safn (museum) is neuter, so its definite form is:

safn → safnið (the museum)
listasafn → listasafnið (the art museum)

So -ið here simply tells you that listasafn is a neuter noun in the definite form.

What grammatical form is skemmtilegra, and why isn’t it just skemmtilegt?

Skemmtilegra is the comparative form of the adjective skemmtilegur (fun, entertaining).

Positive (basic form):
- masculine: skemmtilegur
- feminine: skemmtileg
- neuter: skemmtilegt
Comparative:
- masculine / feminine nominative singular: skemmtilegri
- neuter nominative singular: skemmtilegra

In the sentence:

Listasafnið is neuter nominative singular.
The predicative adjective (the one after er) has to agree with the subject in gender, number, and case.
Therefore we use skemmtilegra (neuter singular comparative), not skemmtilegt (neuter positive).

If you removed the comparison, you would say:

Listasafnið er skemmtilegt. – The art museum is fun.

With the comparative:

Listasafnið er skemmtilegra en … – The art museum is more fun than …

If I am comparing Listasafnið with mörg önnur söfn, why does skemmtilegra only agree with Listasafnið and not with söfn?

In a comparative sentence like this, the adjective describes only the subject, not both sides of the comparison.

Structure:

Listasafnið (subject, neuter singular)
er skemmtilegra (verb + adjective agreeing with the subject)
en mörg önnur söfn (comparison phrase: than many other museums)

The phrase after en just says compared to what?; it does not control agreement. So:

Adjective agrees with Listasafnið → neuter singular: skemmtilegra
The plural söfn is just the other side of the comparison; it doesn’t affect the form of skemmtilegra.

You can see this more clearly if you flip the comparison:

Mörg önnur söfn eru skemmtilegri en Listasafnið.
Many other museums are more fun than the art museum.

Now the subject is plural (mörg önnur söfn), so the comparative adjective is also plural (skemmtilegri).

What exactly does en mean here, and is it the same en that means but?

Yes, it is the same word, but it has two main uses:

With comparatives it means than:
- skemmtilegra en = more fun than
- betri en = better than
- eldri en = older than
In other contexts it often means but:
- Ég kem, en ég verð seinn. – I’m coming, but I’ll be late.

In your sentence, because en follows a comparative (skemmtilegra), it clearly has the meaning than:
Listasafnið er skemmtilegra en mörg önnur söfn. – The art museum is more fun than many other museums.

Why are mörg and önnur in these exact forms, and how do they relate to söfn?

Both mörg and önnur are adjectives that must agree with the noun söfn:

söfn is the plural of safn (museum), and here it is nominative plural neuter.
Adjectives that modify it must also be nominative plural neuter.

Forms:

margur = many
- masculine nom. pl.: margir
- feminine nom. pl.: margar
- neuter nom./acc. pl.: mörg
annar = other, another
- masculine nom. pl.: aðrir
- feminine nom. pl.: aðrar
- neuter nom./acc. pl.: önnur

So:

mörg önnur söfn = many other museums
(all three words are neuter, nominative plural)

Why is the plural of safn written söfn? It looks irregular.

Safn (museum, collection) is a neuter noun with an umlaut in the plural:

Singular: safn [sapn] – a museum
Plural (nom./acc.): söfn [sœpn̥] – museums

What happens:

The a changes to ö in the plural (this is a common historical vowel change in Icelandic, also seen in pairs like barn → börn).
There is no extra plural ending added; the plural is marked mainly by the vowel change: a → ö.
The f and n stay; the spelling just changes a to ö.

You have to memorise these umlaut plurals; they’re very common with neuter nouns in Icelandic.

Is there any word for a or the in mörg önnur söfn, or is Icelandic just leaving articles out?

Icelandic has:

No separate word for an indefinite article (a / an).
A bare noun can mean a museum or museums depending on number and context.
A definite article, but it is almost always a suffix:
- safn – a museum
- safnið – the museum
- söfn – (some) museums
- söfnin – the museums

So mörg önnur söfn literally is just:

mörg – many
önnur – other
söfn – museums

There is no separate article word there. In English we naturally translate it as many other museums; whether you understand it as more like many other museums or many of the other museums depends on context, not on a visible article.

Can the word order in Listasafnið er skemmtilegra en mörg önnur söfn be changed, for example moving er or the adjectives?

Only in limited ways. The main rules at play are:

Verb‑second (V2) in main clauses: the finite verb (er) normally appears in second position.
- Listasafnið (1st element) + er (2nd) + rest of the sentence.
Adjectives come before the noun they modify:
- mörg önnur söfn, not söfn mörg önnur.

Because of V2, you generally cannot move er later, like:

✗ Listasafnið skemmtilegra er en mörg önnur söfn. (incorrect)

You can put a different element in first position (and then the verb still comes second), for example:

Mörg önnur söfn eru skemmtilegri en Listasafnið.
Many other museums are more fun than the art museum.

But the basic pattern [something] + er + … and adjectives before the noun stays the same.

How would I say The art museum is the most fun museum instead of more fun than many other museums?

Here you want the superlative form of skemmtilegur.

Positive: skemmtilegur – fun
Comparative: skemmtilegri / skemmtilegra – more fun
Superlative: skemmtilegastur – most fun (basic masculine form)

Two natural ways to express your idea:

As a predicative adjective (no following noun):
- Listasafnið er skemmtilegast.
  The art museum is the most fun (one).
Explicitly saying the most fun museum:
- Listasafnið er skemmtilegasta safnið.
  The art museum is the most fun museum.

Here skemmtilegasta and safnið are in the weak superlative + definite form, marking that we are talking about the most fun museum in some understood group (for example, in the city).

How do you pronounce the special letters in this sentence, especially ð in Listasafnið and ö in mörg / söfn?

Key sounds:

ð (eth):
- Pronounced like the soft th in English this, that.
- In Listasafnið the ending -nið is [nɪð]; in fast speech the ð can be very soft, almost disappearing, but it is never like English d.
ö:
- A front rounded vowel, similar to German ö in schön or French eu in peur.
- For mörg and söfn, you can approximate it with the vowel in English bird, but with your lips rounded.

Rough pronunciations (stress always on the first syllable):

Listasafnið ≈ LIS‑ta‑sap‑nið
mörg ≈ mœrg (one syllable)
söfn ≈ sœfn (one syllable)