Píanóið í stofunni er mjög stórt.

The piano in the living room is very big.

Breakdown of Píanóið í stofunni er mjög stórt.

• vera: to be
• stórt: big
• mjög: very
• í: in
• stofan: the living room
• píanóið: the piano

Questions & Answers about Píanóið í stofunni er mjög stórt.

Why does píanóið end in -ið? What happened to píanó?

The base noun is píanó (piano). Icelandic usually does not use a separate word for the; instead it adds a definite ending to the noun.

• píanó = a piano
• píanóið = the piano

The ending -ið tells you two things:

1. The noun is neuter (neuter nouns often add -ið in the nominative singular definite).
2. It is definite (the specific piano, not just any piano).

So píanóið literally means the piano.

Why is the adjective stórt and not stór?

Adjectives in Icelandic must agree in gender, number, and case with the noun they describe.

• píanóið is:
  • neuter
  • singular
  • nominative

The basic adjective is stór (big). In the neuter singular nominative, it takes a -t:

• masculine/feminine nominative singular: stór
• neuter nominative singular: stórt

Because píanóið is neuter, you must say stórt, not stór.

So:

• píanóið er stórt = the piano is big
• stóllinn er stór = the chair (masc.) is big
• taskan er stór = the bag (fem.) is big

Why is it í stofunni and not í stofuna?

The preposition í (in/into) can take dative or accusative, depending on the meaning:

• í
  • dative = location (where something is)
• í
  • accusative = motion (where something is going)

In this sentence we are talking about location (the piano is in the living room), so í takes the dative:

• stofa (living room, nominative)
• stofu (dative singular, without article)
• stofunni (dative singular definite: in the living room)

If you talked about moving into the living room, you would use accusative:

• Ég fer í stofuna. = I go into the living room.

What is the relationship between stofa and stofunni? How is stofunni formed?

Stofa is the basic dictionary form (nominative singular):

• stofa = living room

To say in the living room after í (location), you need:

1. Dative singular of stofa: stofu
2. Add the definite ending for feminine dative singular: -nni → stofunni

So the steps are:

• stofa → stofu (dative) → stofu + nni → stofunni
• í stofunni = in the living room

Why is the word order Píanóið í stofunni er mjög stórt? Could I say Í stofunni er píanóið mjög stórt?

The neutral word order is Subject – (place/time) – Verb – (other stuff):

• Píanóið í stofunni er mjög stórt.
  
  • Subject: Píanóið í stofunni
  • Verb: er
  • Predicate: mjög stórt

You can say Í stofunni er píanóið mjög stórt. That is also correct, but it emphasizes the location first: In the living room, the piano is very big.

So both are grammatically fine:

• Píanóið í stofunni er mjög stórt. (more neutral)
• Í stofunni er píanóið mjög stórt. (focuses on in the living room first)

What does mjög mean, and is it always used with adjectives like this?

Mjög means very. It is an adverb that intensifies adjectives and some other words:

• mjög stórt = very big
• mjög falleg = very beautiful
• mjög gott = very good

It does not change form; it stays mjög regardless of gender, number, or case. The adjective changes (stór → stórt), but mjög stays the same.

You typically place mjög directly before the adjective:

• er mjög stórt
• er mjög fallegur, etc.

How do you pronounce the strange letters in píanóið and stofunni?

Key points:

• í: like the ee in see (long, tense i).
• á / ó: long vowels.
  
  • ó is like the o in go, but usually a bit tenser.
• ð in píanóið:
  • After a vowel at the end of a word, ð is usually soft or almost silent.
  • píanóið is roughly [pí-a-no-ith], but the ð is very light, often close to just ending with the vowel.
• Double nn in stofunni:
  • Icelandic double consonants are usually long (geminated).
  • stofunni is roughly [STO-foonn-i] (with a longer n).

You will hear some variation between speakers, but these are good approximations.

What is er here, and does it change with the subject?

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

• Ég er = I am
• Þú ert = you are (singular)
• Hann/Hún/Það er = he/she/it is
• Við erum = we are
• Þið eruð = you are (plural)
• Þeir/Þær/Þau eru = they are

In the sentence Píanóið í stofunni er mjög stórt, the subject píanóið is 3rd person singular, so you use er.

What is the difference between píanó and píanóið in a sentence?

The difference is indefinite vs. definite:

• píanó = a piano (any piano, not specific)
• píanóið = the piano (a specific piano that speaker/listener can identify)

Examples:

• Píanó er dýrt hljóðfæri. = A piano is an expensive instrument. (general statement)
• Píanóið í stofunni er mjög stórt. = The piano in the living room is very big. (we know which piano)

Could the adjective go before the noun, like stórt píanóið í stofunni?

In Icelandic, when the noun is definite (has the article ending), an adjective before it normally takes a weak form and often also has a separate definite article:

• stóra píanóið = the big piano

So:

• Píanóið í stofunni er mjög stórt. = The piano in the living room is very big. (adjective in the predicate, strong form)
• Hið stóra píanó í stofunni = the big piano in the living room (more formal, adjective before noun with separate article hið).

Your suggested stórt píanóið (with -t and the definite ending -ið) is not the normal way to say the big piano. You would use stóra píanóið instead.