Ábyrgðin er mikil.

Icelandic usually shows definiteness by adding an ending to the noun instead of using a separate word like the.

• ábyrgð = responsibility (no article / indefinite or generic)
• ábyrgðin = the responsibility

So Ábyrgðin er mikil literally means “Responsibility-the is great”, which we translate as “The responsibility is great.”

The ending -in is the feminine singular nominative definite ending.

It tells you:

1. The noun is feminine.
2. It is singular.
3. It is in the nominative case (subject).
4. It is definite (the responsibility, not just responsibility).

Compare:

• ábyrgð – responsibility (indefinite / generic)
• ábyrgðin – the responsibility (definite, subject form)
• ábyrgðinni – the responsibility (definite, dative)
• ábyrgðarinnar – of the responsibility (definite, genitive)

The specific shape -in (and not -inn or -ið) matches the noun’s feminine gender.

In Ábyrgðin er mikil:

• Gender: feminine
• Number: singular
• Case: nominative

Reason:

• It’s the subject of the verb er (is), so it must be in the nominative case.
• The base noun ábyrgð is a feminine noun in Icelandic.
• We’re talking about one responsibility, so it’s singular.

So: “feminine singular nominative definite” is the full description of Ábyrgðin here.

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

Present tense of vera:

• ég er – I am
• þú ert – you (sg.) are
• hann / hún / það er – he / she / it is
• við erum – we are
• þið eruð – you (pl.) are
• þeir / þær / þau eru – they are

In Ábyrgðin er mikil, ábyrgðin is 3rd person singular (it), so we use er = is.

The adjective mikill (big, great, much) changes its form to agree with the noun in gender, number, and case.

Nominative singular strong forms:

• Masculine: mikill
• Feminine: mikil
• Neuter: mikið

Since ábyrgðin is feminine singular nominative, the adjective must also be feminine singular nominative strong:

• Ábyrgðin er mikil. – The responsibility is great.

If the noun were neuter, you’d use mikið; if masculine, mikill:

• Verkið er mikið. – The work (neuter) is great / a lot.
• Kostnaðurinn er mikill. – The cost (masc.) is great / high.

Icelandic distinguishes strong and weak adjective declensions:

• Attributive adjectives (directly in front of a definite noun) normally use the weak form:

  • hin mikla ábyrgð – the great responsibility
    
    • mikla = weak feminine nominative singular

• Predicative adjectives (after vera and similar verbs) usually use the strong form, even if the noun is definite:

  • Ábyrgðin er mikil. – The responsibility is great.
    
    • mikil = strong feminine nominative singular

So the rule is about position/function of the adjective:

• before a definite noun → weak
• after to be → generally strong

Yes, you can say:

• Mikil er ábyrgðin.

Grammatically it means the same: “The responsibility is great.”
But the word order changes the emphasis:

• Ábyrgðin er mikil. – neutral / normal statement; basic S–V–C word order.
• Mikil er ábyrgðin. – more emphatic or stylistic, often poetic or formal; the focus is placed on how great the responsibility is.

In everyday speech and writing, Ábyrgðin er mikil is by far more common.

You just add ekki (not) or a degree word like mjög (very):

• Ábyrgðin er ekki mikil.
  – The responsibility is not great.

• Ábyrgðin er mjög mikil.
  – The responsibility is very great.

Word order with ekki after er is the normal pattern for simple negation:

• er ekki = is not

A fairly careful IPA transcription:

• Ábyrgðin er mikil → [ˈauːpɪrɡðɪn ɛr ˈmɪːcɪl]

Some practical tips:

• Á = like ow in cow, but longer: [auː]
• y = a short i sound, like in bit: [ɪ]
• r = trilled or tapped r
• ð = voiced th as in this
• In mikil, the k before i is palatal, somewhat like the k in cute, not like in car.

Rough English-friendly approximation: “OW-birg-thin ehr MEE-kil”, with main stress on Á‑ and MI‑.

ábyrgð has several related meanings, depending on context:

1. Responsibility / duty (moral or practical)

   • Ég ber mikla ábyrgð. – I bear great responsibility.

2. Liability (legal / financial)

   • Ábyrgð bankans – the bank’s liability

3. Guarantee / warranty

   • Tveggja ára ábyrgð á tækinu. – Two‑year warranty on the device.

In Ábyrgðin er mikil, it most naturally reads as responsibility is great, but in the right context it could also be “the liability is great”.

The structure stays the same, but both the noun’s definite ending and the adjective ending change.

Masculine example

• kostnaður – cost, expense (masc.)
• Kostnaðurinn er mikill. – The cost is great / high.

Here:

• kostnaðurinn = masc. sg. nom. definite
• mikill = masc. sg. nom. strong

Neuter example

• verkefni – project, task (neuter)
• Verkefnið er mikið. – The project is big / substantial.

Here:

• verkefnið = neut. sg. nom. definite
• mikið = neut. sg. nom. strong

So you always match the adjective to the gender/number/case of the subject noun.

Yes, there is a subtle difference:

1. Ábyrgðin er mikil.
   – The responsibility is great.
   Focuses on a specific, already known responsibility. “The responsibility (we’re talking about) is large.”

2. Það er mikil ábyrgð.
   – Literally: It is much responsibility.
   More like a general or introductory comment, often translated as:
   – That’s a lot of responsibility. / It’s a big responsibility.

The second structure (Það er…) is common when reacting to new information:

• Þú verður forstjóri? Það er mikil ábyrgð.
  – You’re going to be CEO? That’s a lot of responsibility.