Learn Hardcore Icelandic: Maturinn er íslenskur í kvöld.

So in Maturinn er íslenskur í kvöld, the -inn shows that we are talking about specific food/meal: “the food” (for this evening, at this place), not just food in general.

What exactly does the ending -inn on maturinn tell me?

The ending -inn encodes three things about matur:

Definiteness – it means “the”.
Number – it is singular.
Gender – it is masculine.

So maturinn means “the (masculine, singular) food/meal” in the nominative case (the form used for the subject of the sentence).

Is there ever a separate word for “the” in Icelandic, like in English?

Normally, no. The usual way is to attach the article to the noun:

matur → maturinn (the food)
bíll → bíllinn (the car)
kona → konan (the woman)

There is a separate article “hinn”, but it’s used differently and is rarer in everyday speech, e.g.:

hinn íslenski matur = “the Icelandic food”

In that construction, hinn is more like a demonstrative or emphatic article; for everyday “the X”, you just use maturinn, bíllinn, etc.

Why is the verb er used, and how would it change in other tenses or persons?

er is the 3rd person singular present form of the verb vera (“to be”):

ég er – I am
þú ert – you (sg.) are
hann / hún / það er – he / she / it is

In your sentence, maturinn is 3rd person singular (“it”), so you use er.

Other tenses with maturinn:

Maturinn var íslenskur í gær. – The food was Icelandic yesterday.
Maturinn verður íslenskur á morgun. – The food will be Icelandic tomorrow.

Why is it íslenskur and not íslenskt or íslensk?

Adjectives in Icelandic agree with the noun in gender, number, and case.

maturinn is masculine, singular, nominative.
So the adjective must also be masculine singular nominative (strong form):
- íslenskur = masculine singular nominative (strong)
- íslensk = feminine singular nominative (strong)
- íslenskt = neuter singular nominative/accusative (strong)

Because matur is grammatically masculine, you must say:

Maturinn er íslenskur. – The food is Icelandic.

Not íslenskt or íslensk.

Does íslenskur agree with the meaning of “food” (like mass/thing), or with grammatical gender?

It agrees with grammatical gender, not with the type of thing in the real world.

Even though “food” feels like a neutral mass concept in English, the Icelandic word matur is grammatically masculine, so the adjective uses masculine forms:

maturinn er íslenskur – the food is Icelandic (masc.)
súpan er íslensk – the soup is Icelandic (because súpa is feminine)
lagið er íslenskt – the song is Icelandic (because lag is neuter)

So you always follow the dictionary gender of the noun.

Would Maturinn er íslenski be correct, since the noun is definite?

No, Maturinn er íslenski is incorrect in normal Icelandic.

Two key points:

Predicative adjectives (after verbs like vera “to be”) usually take the strong declension, even when the noun is definite.
- So: Maturinn er íslenskur. (strong form)
The weak masculine nominative form would be íslenski, but that is used when the adjective stands in front of a definite noun:
- íslenski maturinn – the Icelandic food
- hinn íslenski matur – the Icelandic food

So:

After er: Maturinn er íslenskur. ✅
Before the noun: íslenski maturinn ✅
Maturinn er íslenski. ❌ in standard usage

What case are maturinn and íslenskur in, and why?

Both are in the nominative case:

maturinn is the subject of the sentence → nominative.
íslenskur is a predicative adjective describing the subject → it also appears in nominative, agreeing with the subject.

With the verb “vera” (to be), the complement (adjective or noun) typically matches the subject’s case, so they both end up in nominative here.

Why is í kvöld at the end, and could it go somewhere else in the sentence?

Í kvöld is a time expression (“tonight / this evening”). In Icelandic, adverbials like this are fairly flexible in position.

Neutral version:

Maturinn er íslenskur í kvöld.

Common alternative:

Í kvöld er maturinn íslenskur. – “Tonight, the food is Icelandic.”

Both are correct. Moving í kvöld to the front often adds emphasis to the time (“As for tonight…”). Note that Icelandic keeps the finite verb in second position, so when you front Í kvöld, the verb er stays second:
Í kvöld er maturinn íslenskur.

Why doesn’t kvöld change after í? Shouldn’t there be some ending?

The preposition í can take either accusative or dative, depending on meaning. In time expressions like í kvöld (“this evening / tonight”), it takes the accusative.

The noun kvöld (“evening” / “night”) is neuter, and in the singular its nominative and accusative forms are identical: kvöld.

So:

Formally, it is in the accusative.
You just don’t see a difference because nominative = accusative for this word in the singular.

Other time expressions are similar:

í dag – today
í gær – yesterday

Does maturinn here mean “the food” in general, or more like “the dinner / the meal”?

Context decides, but very often maturinn in a sentence about a specific time (like í kvöld) is best understood as “the meal (we’re having)”, i.e. “dinner/supper”.

So:

Maturinn er íslenskur í kvöld.
- Natural reading: “The dinner/meal tonight is Icelandic.”
- It can also be understood as “The food (we’re serving/eating) tonight is Icelandic.”

How would I say “Tonight the food is not Icelandic” or “The food was Icelandic last night”?

You add ekki for negation, and change the verb form for past tense:

Tonight the food is not Icelandic.
- Maturinn er ekki íslenskur í kvöld.
The food was Icelandic last night.
- Maturinn var íslenskur í gærkvöldi.
  - (var = past of er,
    í gærkvöldi = last night / yesterday evening)

Could I say Í kvöld er íslenskur matur instead, and what’s the difference?

Yes, that is correct, but the nuance changes slightly:

Í kvöld er íslenskur matur.
- Literally: “Tonight there is Icelandic food.”
- íslenskur matur is indefinite (“Icelandic food” in general).
Í kvöld er maturinn íslenskur.
- Literally: “Tonight the food is Icelandic.”
- maturinn is definite (“the (planned/specific) meal”).

So:

íslenskur matur = some Icelandic food (indefinite).
maturinn er íslenskur = the particular meal we have tonight is Icelandic (definite).