Learn Hardcore Icelandic: Pósthúsið lokar seint í dag, því miður. - The post office closes late today, unfortunately.

Icelandic uses a suffixed definite article. The noun pósthús (neuter) becomes pósthúsið in the definite nominative/accusative singular. So pósthúsið means the post office.

What case is pósthúsið here, and how can I tell?

It’s nominative singular. It’s the subject of the verb lokar (closes). Neuter nouns have the same form in nominative and accusative, but since it’s the subject, nominative is intended.

Why is the verb loka conjugated as lokar?

Lokar is the 3rd person singular present tense, matching the singular subject (pósthúsið). Present tense of að loka:

ég loka
þú lokar
hann/hún/það lokar
við lokum
þið lokið
þeir/þær/þau loka

Does loka take an object, and if so, which case?

Yes, when it’s transitive, loka governs the dative: you loka einhverju (close something). Example: loka hurðinni (close the door – dative). In your sentence it’s intransitive: the post office closes.

Why not use lokast instead of lokar?

Lokast is the middle/passive form meaning gets closed/ends up closed. It’s used for things that close by themselves or for the state change (e.g., Hurðin lokast – the door closes). For scheduled closing times of a business, lokar is the natural choice.

Why is the present tense used for something happening later today?

Icelandic commonly uses the present for scheduled or timetabled future events, especially with time expressions like í dag. Mun loka (will close) is possible but not necessary here; it can sound more predictive or emphatic.

How does the word order work with seint and í dag?

Default order is Subject–Verb–Adverbial(s). The phrase seint í dag functions as a time adverbial chunk and naturally follows the verb: Pósthúsið lokar seint í dag. You can front the time for emphasis: Í dag lokar pósthúsið seint. Avoid splitting it unnaturally (e.g., placing í dag and seint far apart).

What’s the difference between seint and seinna?

Seint = late (absolute), e.g., seint í dag (late today – near the end of the day).
Seinna = later (comparative), e.g., seinna í dag (later today – at some point later than a reference time, not necessarily late in the day).

Is seint an adverb or an adjective? What about forms like seinn/sein/seint?

Seint is the adverb (late) used to modify verbs: Ég kom seint (I arrived late).
The adjective is seinn (m.), sein (f.), seint (n.) meaning late (as a property of a person/thing): Ég er seinn (masc.), Hún er sein (fem.).

Why is it í dag and not something like í daginn?

Í dag is a fixed time expression meaning today; no article is used. Icelandic has several fixed patterns for time:

í dag, í gær, í kvöld
but á morgun So you say í dag, not í daginn.

What case is dag in í dag, and why not degi?

It’s accusative singular. With time expressions, í typically takes the accusative. The noun dagur declines: nominative dagur, accusative dag, dative degi, genitive dags.

Why is there a comma before því miður?

Því miður is a parenthetical sentence adverb meaning unfortunately. It’s commonly set off by a comma (or parentheses/dashes) to show it comments on the whole sentence: …, því miður.

Where can I place því miður in the sentence?

Flexible positions are fine:

Initial: Því miður lokar pósthúsið seint í dag.
Medial (parenthetical): Pósthúsið, því miður, lokar seint í dag.
Final: Pósthúsið lokar seint í dag, því miður. Final position is very natural in speech.

What does því miður literally mean, and are there related expressions?

Literally something like by/for that, worse (an old comparative), but it’s an idiom you should just learn as unfortunately. A useful counterpart is sem betur fer (fortunately).

How would I say “The post office closes early today” instead?

Use snemma (early): Pósthúsið lokar snemma í dag.

How do I say it closes at a specific time?

Use klukkan + time: Pósthúsið lokar klukkan sjö (The post office closes at seven). You can combine with today: Pósthúsið lokar klukkan sjö í dag.

Could I say “The post office is closed” to talk about state rather than the action?

Yes: Pósthúsið er lokað (It is closed). That describes the state. Pósthúsið lokar describes the action/time of closing.

Pronunciation tips for key bits?

þ in því: voiceless th (as in thin).
ð in miður: voiced th (as in this).
ó in póst-: like the vowel in English go.
ei in seint: like the vowel in English eight.
g in dag: often a soft fricative near the end (not a hard g).
r is trilled or tapped.
Word stress is on the first syllable of each word: PÓSThúsið, LÓkar, SEINT, ÞVÍ MIður.

Why is Pósthúsið capitalized?

Only because it begins the sentence. As a common noun, it’s lowercase: pósthúsið in the middle of a sentence.

Is því miður required?

No. It just adds the speaker’s regret. Without it, Pósthúsið lokar seint í dag is a neutral statement of fact.