Gítarinn er í stofunni.

The ending -inn is the definite article attached to the noun.

• gítar = guitar
• gítarinn = the guitar

In Icelandic, the word the is usually not a separate word; instead it is added to the end of the noun as a suffix (with different forms: -inn, -an, -ið, -nir, -arnir, -in, -urnar, etc., depending on gender/number/case).

You would remove the definite endings from both nouns:

• Gítar er í stofu. = A guitar is in a living room.

More literally:

• gítar = a guitar (indefinite)
• stofa = a living room (indefinite, nominative form; after í here you use stofu, the accusative form; see below).

In everyday use, Gítar er í stofu sounds a bit unusual out of context; Icelandic often prefers the definite versions when talking about specific, known things: Gítarinn er í stofunni.

There are two things going on:

1. Definiteness

   • stofa = a living room
   • stofan (nom.) / stofunni (dat.) = the living room
     Since the English sentence is in the living room, Icelandic uses the definite form → stofunni.

2. Case after the preposition í

   • í can take either dative or accusative, depending on meaning:
     
     • Dative: location (where something is)
     • Accusative: movement into (where something goes)

   In Gítarinn er í stofunni, we describe location (the guitar is in the living room), so í takes the dative case.

   The dative singular form of stofa is stofu; then you add the definite ending -nni → stofunni.

The base form is stofa (a feminine noun meaning living room or sometimes sitting room / lounge).

Singular:

• Nominative: stofa – a living room
• Accusative: stofu
• Dative: stofu
• Genitive: stofu

With the definite article (singular):

• Nominative: stofan – the living room
• Accusative: stofuna
• Dative: stofunni
• Genitive: stofunnar

So stofunni is: stofa + dative singular + definite ending → the living room (in dative).

Í can mean both in and into, and the case tells you which is meant:

• Dative = location (where?)
  • Gítarinn er í stofunni.
    The guitar is in the living room. (no movement)
• Accusative = movement (to where?)
  • Ég fer í stofu.
    I go into a living room / I go to the living room.

Same preposition, different case:

• í stofunni (dative) = inside, at rest
• í stofu (accusative) = into, towards

No. In Icelandic, common nouns are normally not capitalized, just like in English.

So in ordinary text you would write:

• gítarinn er í stofunni.

In a teaching example, dictionary heading, or beginning of a sentence, you may see it capitalized because it’s the first word:

• Gítarinn er í stofunni.

So the capital G is because it’s the first word of the sentence, not because gítar must be capitalized.

Gítar is a masculine noun.

Its singular forms (indefinite/definite) are:

• Nominative: gítar / gítarinn – a/the guitar
• Accusative: gítar / gítarinn
• Dative: gítar / gítarnum
• Genitive: gítars / gítarsins

In Gítarinn er í stofunni, Gítarinn is the subject of the sentence, so it is in the nominative case, and because it’s the guitar, you use the definite ending -inn.

You could say Gítar er í stofunni, but it would sound quite odd in most normal contexts, a bit like saying Guitar is in the living room in English—missing the article.

In Icelandic:

• for a specific known item, you almost always use the definite form:
  
  • Gítarinn er í stofunni. – The guitar is in the living room.
• for an unspecified guitar, you would usually change the structure so it sounds natural, for example:
  
  • Það er gítar í stofunni. – There is a guitar in the living room.

Er is the 3rd person singular present tense of the verb vera (to be). It works just like is in English.

• vera = to be
• ég er = I am
• þú ert = you are
• hann / hún / það er = he / she / it is

So:

• Gítarinn er í stofunni.
  literally = The guitar is in the living room.

Both are grammatically correct:

• Gítarinn er í stofunni.
  Neutral, normal word order: subject–verb–location.

• Í stofunni er gítarinn.
  This puts emphasis on the location, roughly:
  In the living room is the guitar. (i.e. that’s where it is.)

Icelandic allows this fronting of adverbials (like í stofunni) for emphasis or style, but the neutral order is Gítarinn er í stofunni.

You make both nouns plural and definite:

• Gítararnir eru í stofunni.

Breakdown:

• gítarar = guitars (plural)
• gítararnir = the guitars (plural definite)
• eru = are (3rd person plural of vera)
• í stofunni = in the living room (same as before; the living room is still just one room, so singular dative definite).

Approximate IPA and an English-style guide:

• Gítarinn → [ˈciːtarɪn]

  • í as in see
  • gít- sounds a bit like geet- but with a softer g (often like ky before í)
  • -arinn like ar-in

• er → [ɛr]

  • like air but shorter

• í → [iː]

  • like ee in see

• stofunni → [ˈstɔːvʏnɪ] (roughly)

  • sto- like stoh- (as in story, but shorter and more open)
  • -fu- is like fu in full, but with rounded lips
  • -nni like nni in funny but with a clearer i

Spoken smoothly:
[ˈciːtarɪn ɛr iː ˈstɔːvʏnɪ]
Rough English-like hearing: “KEE-tar-in air ee STOH-vu-nni”.