Learn Hardcore Icelandic: Eftir hádegismat spjöllum við saman í stuttu hléi. - After lunch we chat together in a short break.

Eftir – preposition meaning after.
hádegismat – noun meaning lunch, here in an oblique case (accusative/dative form hádegismat) governed by eftir. Together eftir hádegismat = after lunch.
spjöllum – finite verb, we chat / we talk (1st person plural present of spjalla).
við – personal pronoun, we, nominative plural; the subject of the verb spjöllum.
saman – adverb meaning together.
í – preposition meaning in / during, here used for time.
stuttu – adjective stuttur (short), in dative neuter singular (stuttu) agreeing with hléi.
hléi – noun hlé (break, pause), in dative singular (hléi), governed by í.

Structure:

Prepositional phrase of time: Eftir hádegismat
Verb: spjöllum
Subject: við
Adverb: saman
Prepositional phrase of time: í stuttu hléi

Why does the verb spjöllum come before við? In English we would say “we chat,” not “chat we.”

Icelandic main clauses generally follow a verb-second (V2) word order rule:

The first position can be almost anything (subject, adverb, prepositional phrase, etc.).
The finite verb then must come in second position.
The rest of the elements follow.

In your sentence, the first position is taken by the time phrase:

Eftir hádegismat – first position
spjöllum – the finite verb in second position
við – the subject, following the verb

If you instead started with the subject, the order would look more like English:

Við spjöllum saman eftir hádegismat í stuttu hléi.

This is also correct. In both versions, the verb is in second position:

Eftir hádegismat spjöllum við …
Við spjöllum …

What exactly is spjöllum? What is the infinitive and how is it conjugated?

The verb is spjalla (to chat, to have a talk).

Spjöllum is:

present tense
1st person plural
indicative mood

Present indicative of spjalla:

ég spjalla – I chat
þú spjallar – you (sing.) chat
hann / hún / það spjallar – he / she / it chats
við spjöllum – we chat
þið spjallið – you (pl.) chat
þeir / þær / þau spjalla – they chat

Note the vowel change a → ö in spjöllum; that’s a regular sound change in many Icelandic verb forms and doesn’t change the basic meaning.

Why is it hádegismat and not hádegismatur?

The base noun is hádegismatur (lunch), masculine.

Icelandic nouns change form according to case. The nominative singular is:

hádegismatur – used for the subject of a sentence.

But here the word follows the preposition eftir, so it must be in an oblique case (non-nominative). For this noun, the singular accusative and dative forms are:

hádegismat – accusative singular
hádegismat – dative singular

So hádegismat is the correct oblique form required after eftir in a time expression. You never say eftir hádegismatur in correct Icelandic.

Is hádegismat a compound? What does it literally mean?

Yes, hádegismatur is a compound noun:

hádegi – noon
matur – food, meal

Together hádegismatur literally means noon-meal, i.e. lunch.

In the sentence, we see the oblique form hádegismat (because of the preposition), but the lexical (dictionary) form is hádegismatur.

In í stuttu hléi, what would the basic, dictionary form of this phrase be, and how is it declined?

The underlying “bare” phrase is:

stutt hlé – short break

Here:

hlé is a neuter noun. Nominative singular: hlé.
stuttur is the adjective short. In nominative neuter singular, it is stutt.

So in nominative (as a simple subject or object) you’d have:

stutt hlé – a short break

In the sentence, í governs the dative when talking about being in a period of time, so both the noun and adjective go to dative singular neuter:

hlé → hléi (dative singular neuter)
stutt → stuttu (dative singular neuter, strong adjective)

Hence:

í stuttu hléi – in/during a short break

Why is there no word for “a” in í stuttu hléi, even though English says “in a short break”?

Icelandic has:

definite articles, attached as endings to nouns (for example hléið = the break), and
no separate indefinite article (“a / an” does not exist as a word).

So where English says:

in a short break

Icelandic simply uses:

í stuttu hléi

The absence of a definite ending (no -ið, -inn, etc.) plus context gives the natural reading a short break rather than the short break.

If you wanted to say in the short break, you would use the definite form:

í stutta hléinu (dative singular of the definite form stutta hléið).

Why is the preposition í used with hlé? Could you say something else like á stuttu hléi?

With hlé (a break, pause), the common idiomatic preposition for being “in that time period” is í:

í hléi – during a break
í stuttu hléi – during a short break

You will hear expressions like:

Við tökum kaffi í hléi. – We have coffee during the break.

Using á with hlé in this time sense is not idiomatic. Á + dative is often used with days or more “surface-like” time points (á mánudögum, á kvöldin), but í hléi is the established collocation for “during (the) break.”

Do we really need saman? Doesn’t við spjöllum already imply “we talk together”?

Grammatically, við spjöllum already means we chat and it is clear that the speakers are doing the action jointly.

However, saman adds explicit emphasis on together / with each other. It has a similar nuance to English:

We talk versus We talk together.

So:

Við spjöllum í stuttu hléi. – We chat in a short break.
Við spjöllum saman í stuttu hléi. – We chat together in a short break (with each other; more social/interactive in feel).

You can omit saman without making the sentence ungrammatical; it just slightly changes the emphasis.

Can I change the word order, for example: Við spjöllum saman eftir hádegismat í stuttu hléi?

Yes. Icelandic allows quite a bit of word-order flexibility, as long as:

The finite verb remains in second position in main clauses.
You don’t break fixed expressions in unnatural ways.

All of the following are grammatical (with slightly different information structure or emphasis):

Eftir hádegismat spjöllum við saman í stuttu hléi.
– Emphasis starts on after lunch.
Við spjöllum saman eftir hádegismat í stuttu hléi.
– More neutral; starts from the subject we.
Í stuttu hléi eftir hádegismat spjöllum við saman.
– Fronts the whole time phrase in a short break after lunch.

In each, the finite verb (spjöllum) is second, and the prepositional time phrases can move to highlight different parts of the sentence.

What tense or aspect does spjöllum express? Is this a habitual action?

Spjöllum is present tense, indicative mood.

In Icelandic, the present tense covers:

ongoing present: what is happening now
general/habitual present: what happens regularly, by habit
scheduled future in some contexts (similar to English “We leave tomorrow”).

So a sentence like this most naturally expresses a habitual or regular action:

(Typically) after lunch, we chat together during a short break.

If you wanted to clearly mark the future or a one-time plan, you might use:

Eftir hádegismat munum við spjalla saman í stuttu hléi.
– After lunch, we will chat together in a short break.

Is the sentence formal, informal, or neutral? In what context does it sound natural?

The sentence is neutral and natural, and would fit in everyday spoken or written Icelandic. It is neither especially formal nor slangy.

Typical contexts:

Describing a routine at work or school
- e.g. explaining your daily schedule to someone.
Explaining a plan for the day in a fairly neutral tone.

It would sound fine in:

an email to colleagues,
a conversation with a friend,
a description in a textbook or a schedule.