Learn Hardcore Icelandic: Eftir hugleiðslu líður henni frjáls og róleg allan daginn. - After meditation she feels free and calm all day.

Here, henni is in the dative case and functions as the experiencer of the feeling. Many “feeling” or “experiencer” verbs in Icelandic take the person in the dative:

Mér líður vel. – I feel good.
Honum líður illa. – He feels bad.

If you say “hún líður”, that normally means “she passes / she elapses”, the same use as in:

Tíminn líður hratt. – Time passes quickly.

So for “she feels…”, you must say “Henni líður …”, not “Hún líður …”.

Why is the word order “Eftir hugleiðslu líður henni …”? Could I say “Eftir hugleiðslu henni líður …”?

Icelandic main clauses follow a verb-second (V2) rule: the finite verb (here líður) usually comes second in the sentence, no matter what comes first.

In your sentence:

Eftir hugleiðslu – fronted time phrase (position 1)
líður – finite verb (position 2)
henni frjáls og róleg allan daginn – rest of the clause

So:

Eftir hugleiðslu líður henni frjáls og róleg allan daginn. ✅

If you move the time phrase to the end, the more “neutral” order is:

Henni líður frjáls og róleg allan daginn eftir hugleiðslu. ✅
(Now henni is first, so líður comes second.)

But “Eftir hugleiðslu henni líður …” breaks the V2 pattern (the verb is third), so it is not good Icelandic.

What exactly is “henni” here, and how does it differ from “hún” and “hana”?

These are all forms of the 3rd person singular feminine pronoun (“she”):

hún – nominative (subject form)
hana – accusative (direct object)
henni – dative (indirect object / experiencer)
hennar – genitive (of her)

The verb líða (in the “to feel” sense) requires the experiencer in the dative, so we must use henni:

Henni líður frjáls og róleg. – She feels free and calm.
Mér líður vel. – I feel good.
Okkur líður betur núna. – We feel better now.

So henni is not a separate word for “her” in some abstract way; it is simply the dative form of hún required by this verb.

Why is it “hugleiðslu” and not “hugleiðsla”?

The base noun is:

hugleiðsla – meditation (noun, feminine, “weak” -a type)

Its singular forms are:

Nom: hugleiðsla
Acc: hugleiðslu
Dat: hugleiðslu
Gen: hugleiðslu

After the preposition eftir, you need an oblique case (accusative or dative, depending on meaning). For time expressions like “after meditation”, you put the noun in the oblique form, which here is hugleiðslu.

So:

Eftir hugleiðslu – After meditation

You don’t see a visible difference between accusative and dative here because for this type of feminine noun, both are -u in the singular.

Which case does “hugleiðslu” actually have after “eftir”?

The preposition eftir can govern more than one case, and with many nouns in the singular, the forms overlap:

With time / sequence meanings like after (an event / a period), you’ll see an oblique form (accusative or dative), and for many learners it’s enough to remember “eftir + [oblique form]”*.

The important practical point:

After eftir in this meaning, you do not use the nominative.
You use a non-nominative form: here hugleiðslu is that form.

Since hugleiðsla has hugleiðslu for both acc. and dat. in the singular, you cannot see a difference in the sentence; it is simply “the form required after eftir in this expression”.

Why are the adjectives “frjáls” and “róleg” in those forms? Shouldn’t they agree with henni in dative (like frjálsri/rólegri)?

The adjectives frjáls and róleg describe the logical subject hún (“she”), even though the experiencer is in dative (henni). With verbs like að vera (to be) and að líða (to feel), the predicative adjectives agree in nominative with the underlying subject, not in dative with the experiencer form.

You can think of:

Henni líður frjáls og róleg. ≈ Hún er frjáls og róleg.
(She feels free and calm ≈ She is free and calm.)

So we use nominative feminine singular:

frjáls – nominative feminine singular (same form as masculine here)
róleg – nominative feminine singular (from rólegur, “calm”)

Forms like frjálsri / rólegri are dative feminine, and would be wrong in this predicative use. Icelandic does not make the adjective agree with the dative experiencer here; it agrees with the understood nominative subject.

Could I say “frjálsa og rólega” instead of “frjáls og róleg”?

Not with this meaning.

frjáls, róleg – adjectives (free, calm), describing her state
frjálsa, rólega – usually the adverbial forms (freely, calmly), describing how something is done

Your sentence is:

Eftir hugleiðslu líður henni frjáls og róleg allan daginn.
After meditation she feels free and calm all day.

Here, we want adjectives that describe what she is / feels like, not how she does something. So we keep the adjectives:

Henni líður frjáls og róleg. ✅
Henni líður frjálslega og rólega. – would mean something more like she feels in a free and calm way, which is odd.

Use frjáls, róleg (adjectives) with líður when you describe a state.

What does “allan daginn” mean grammatically, and why is it in that form?

Allan daginn is an accusative of duration: it expresses how long something lasts.

Breakdown:

allur – “all, whole” (adjective, masculine)
- Masc. acc. sg.: allan
dagur – “day” (noun, masculine)
- Acc. sg. definite: daginn (the day)

So:

allan daginn = the whole day / all day long (accusative)

Icelandic commonly uses the accusative for time spans:

Ég vann allan daginn. – I worked all day.
Hann svaf alla nóttina. – He slept all night.

In your sentence, it tells us how long she feels that way:

… líður henni frjáls og róleg allan daginn.
… she feels free and calm all day.

Does “allan” describe her or the day? What exactly is “allan daginn” attached to?

Allan goes with daginn, not with henni.

Structurally, you have:

Henni – the experiencer (dative pronoun)
frjáls og róleg – adjectives describing her state
allan daginn – a separate time phrase modifying the whole situation

So you can think:

Henni líður [frjáls og róleg] [allan daginn].
She feels [free and calm] [all day long].

It does not mean that she herself is “all” in any grammatical sense; allan is only part of the time expression allan daginn.

Can I move “allan daginn” to another position, like “Eftir hugleiðslu líður henni allan daginn frjáls og róleg”?

Yes, adverbial time phrases in Icelandic are fairly flexible. All of these are acceptable and natural, with slightly different emphasis:

Eftir hugleiðslu líður henni frjáls og róleg allan daginn.
Eftir hugleiðslu líður henni allan daginn frjáls og róleg.
Henni líður frjáls og róleg allan daginn eftir hugleiðslu.

What you must keep is the verb-second rule:

The finite verb (líður) should still be second element in the main clause.
Moving allan daginn around is fine as long as you don’t push líður out of second position or break up phrases unnaturally.

Could I say something like “Eftir að hún hefur hugleitt líður henni frjáls og róleg allan daginn” instead of “eftir hugleiðslu”?

Yes. Both structures are possible; they just phrase the “after” part differently:

Noun phrase:
- Eftir hugleiðslu líður henni frjáls og róleg allan daginn.
  – After meditation she feels free and calm all day.
Clause with “eftir að”:
- Eftir að hún hefur hugleitt líður henni frjáls og róleg allan daginn.
  – After she has meditated, she feels free and calm all day.

The meaning is very close. Differences:

Eftir hugleiðslu is shorter and more neutral; it treats “meditation” as an event or activity.
Eftir að hún hefur hugleitt highlights her doing the action (it’s more explicit and a bit more formal / explicit in style).

For everyday speech and writing, eftir hugleiðslu is perfectly natural and idiomatic.