Learn Hardcore Icelandic: Staðurinn er rólegri núna.

staður = place
-inn (attached to staðurinn) = the (definite article)
→ staðurinn = the place
er = is (3rd person singular of vera – to be)
rólegur = quiet / calm (base form of the adjective)
rólegri = quieter / more quiet (comparative form of rólegur)
núna = now

So the whole sentence means: The place is quieter now.

Why is staðurinn one word instead of saying staður + “the” as in English?

Icelandic does not use a separate word for the the way English does.
Instead, it usually attaches a definite article ending to the noun:

staður = place
staðurinn = the place

Some more examples:

bíll = car → bíllinn = the car
stóll = chair → stóllinn = the chair
bók = book → bókin = the book

So staðurinn is simply staður + -inn (the), written as one word.

Why is staðurinn in this form? What case is it, and how can I tell?

In Staðurinn er rólegri núna, staðurinn is the subject of the sentence, so it appears in the nominative case.

Very roughly:

Subjects of simple sentences are in nominative.
Things directly acted on (direct objects) are usually in accusative.
There are also dative and genitive, but you don’t need them yet for this sentence.

Here:

Subject: staðurinn (the place) → nominative
Verb: er
Complement (what the subject “is”): rólegri (quieter)

So whenever a noun is the thing that is / does something, its basic dictionary form plus definite ending is often nominative, as with staðurinn.

What is the base form of rólegri, and how is the comparative formed?

The base (positive) form is:

rólegur = quiet, calm

Comparative (used to say “quieter / more quiet”):

rólegur → rólegri (masculine/feminine)
rólegur → rólegra (neuter)

So:

Hann er rólegur. = He is quiet.
Hann er rólegri. = He is quieter.
Húsið er rólegt. = The house is quiet. (neuter)
Húsið er rólegra. = The house is quieter. (neuter comparative)

In your sentence:

staðurinn is masculine, so the correct comparative form is rólegri.

Does rólegri have to “agree” with staðurinn in gender, number, and case?

Yes, in Icelandic an adjective generally agrees with the noun it describes in:

Gender (masculine / feminine / neuter)
Number (singular / plural)
Case (nominative / accusative / dative / genitive)

Here:

staðurinn is masculine singular nominative (subject).
rólegri is also in masculine singular nominative (comparative) to match it.

If the noun changed, the adjective form could change too. For example:

Staðurinn er rólegri. = The place (masc. sg.) is quieter.
Húsið er rólegra. = The house (neut. sg.) is quieter.
Staðirnir eru rólegri. = The places (masc. pl.) are quieter.

So yes, rólegri is shaped by the noun it describes.

What is the difference between rólegur and rólegri in this kind of sentence?

rólegur (base form) → quiet / calm
rólegri (comparative) → quieter / more quiet

So:

Staðurinn er rólegur núna.
= The place is quiet now.
Staðurinn er rólegri núna.
= The place is quieter now (quieter than before or than somewhere else).

The comparative -ri form always implies some kind of comparison: before vs now, here vs there, this place vs that place, etc., even if it’s not explicitly stated.

What does núna mean exactly, and how is it different from nú?

Both núna and nú can mean now, but:

núna is often a bit more concrete / situational: right now, at this moment, these days.
nú can be more flexible: it can mean now, or work a bit like a discourse word (“now, listen”, “well, now…”).

In your sentence, both are possible, with little difference in everyday speech:

Staðurinn er rólegri núna.
Staðurinn er rólegri nú.

For a learner, you can safely treat núna as “now (at the present time)” and use it like now in English at the end of the sentence.

Can the word order change? For example, can I say Núna er staðurinn rólegri?

Yes. Icelandic has flexible word order, but follows a verb-second (V2) rule in main statements: the finite verb (here, er) normally comes in second position.

Both of these are correct:

Staðurinn er rólegri núna.
- Subject first: The place is quieter now.
Núna er staðurinn rólegri.
- Time word first: Now the place is quieter. (slight emphasis on now)

In both, the verb (er) is in second position:

[Staðurinn] er [...]
[Núna] er [...]

You generally wouldn’t say *Staðurinn núna er rólegri in normal speech.

Can I leave out núna? What changes in meaning?

Yes, you can say just:

Staðurinn er rólegri.
= The place is quieter.

Without núna, the sentence still compares the level of quietness, but it doesn’t specify when. The comparison could be:

Now vs earlier
This place vs another place
After vs before some event

Adding núna makes it clear that the comparison is about time:
The place is quieter now (than it was before).

How do I say similar sentences in other tenses or degrees, like “was quieter” or “is the quietest”?

Using the same adjective, you can change the tense or degree:

Past tense (was quieter):

Staðurinn var rólegri.
= The place was quieter.

Superlative (the quietest / most quiet):

Base → Comparative → Superlative (masc. nom. sg.):

rólegur → rólegri → rólegastur

Examples:

Staðurinn er rólegastur núna.
= The place is (the) quietest now.

Neuter example:

Húsið er rólegast.
= The house is quietest / the quietest.

You keep the same pattern: subject + vera (er/var/mun vera, etc.) + adjective form.

How do I pronounce Staðurinn er rólegri núna?

Approximate pronunciation (using English-like hints):

Staðurinn ≈ STHA-thu-rin
- Stað-: stað with ð like th in this (voiced).
- Stress on the first syllable: STÁ-ðurinn.
er ≈ air (short, like e in bed, then r)
rólegri ≈ ROH-legh-ri
- ró: long o, like in row.
- g before r is soft, almost like a voiced gh sound.
núna ≈ NOO-na
- nú: like new but with a pure oo sound.

Very roughly all together:

STHA-thu-rin air ROH-legh-ri NOO-na

Remember: in Icelandic, stress is almost always on the first syllable of each word.

Why is it Staðurinn er rólegri núna and not something like Þessi staður er rólegri núna (“this place is quieter now”)?

You can say:

Þessi staður er rólegri núna.
= This place is quieter now.

That uses þessi = this (demonstrative) + staður (indefinite noun).

But Staðurinn er rólegri núna is slightly different:

It assumes that both speaker and listener know which place is being talked about (it’s “the” specific place in context).
Using the definite ending -inn is often more natural for familiar or previously mentioned places.

Very roughly:

Þessi staður er rólegri núna.
→ This place (here/that we’re pointing at) is quieter now.
Staðurinn er rólegri núna.
→ The place (we both know which one) is quieter now.

Both are grammatically correct; the original just uses the rather than this.