Ég nota gagnagrunninn.

In Icelandic, the is usually attached to the end of the noun instead of being a separate word.

So:

• gagnagrunnur = database
• gagnagrunninn = the database in this sentence

The ending -inn is the definite article here.

Because gagnagrunninn is the accusative singular definite form, and nota takes a direct object in the accusative.

• gagnagrunnurinn = the database as a subject of a sentence
• gagnagrunninn = the database as a direct object

Compare:

• Gagnagrunnurinn er stór. = The database is big.
• Ég nota gagnagrunninn. = I use the database.

So the form changes because of case.

The dictionary form is gagnagrunnur.

Icelandic dictionaries normally list nouns in the nominative singular indefinite form. So if you want to look this word up, search for gagnagrunnur, not gagnagrunninn.

Useful forms here are:

• gagnagrunnur = nominative singular, indefinite
• gagnagrunn = accusative singular, indefinite
• gagnagrunninn = accusative singular, definite

It is accusative singular.

The reason is that nota normally takes its object in the accusative case. In this sentence, the database is the thing being used, so it is the direct object.

This is something English speakers often have to get used to in Icelandic: the form of a noun changes depending on its role in the sentence.

The infinitive is að nota = to use. The að is the infinitive marker, and the verb itself is nota.

In the present tense, first person singular is also nota:

• ég nota = I use

That is why the verb looks the same as the dictionary form.

A few present-tense forms:

• ég nota
• þú notar
• hann/hún/það notar
• við notum
• þið notið
• þeir/þær/þau nota

In normal Icelandic, you usually do need the subject pronoun.

So Ég nota gagnagrunninn is the normal full sentence.

Unlike some languages such as Spanish or Italian, Icelandic does not usually drop subject pronouns in ordinary statements. Leaving out ég would sound incomplete in most contexts.

Yes, but the neutral word order here is:

• Ég nota gagnagrunninn.
  I use the database.

Icelandic does allow other word orders for emphasis or style, but it follows a strong verb-second pattern.

For example:

• Gagnagrunninn nota ég.
  This is possible, but it sounds more marked or contrastive, like The database is what I use.

• Í dag nota ég gagnagrunninn.
  Today I use the database.

Notice that when something else comes first, the finite verb nota still stays in second position.

Because gagnagrunnur is a compound word.

It is built from:

• gögn = data, documents, records
• grunnur = base, foundation

The first part appears as gagna-, which is a common compound form based on the genitive plural. So the word is literally something like data-base.

This kind of compounding is very common in Icelandic.

The é in Icelandic is a separate vowel letter, not just a stress mark.

In ég, it is pronounced roughly with a y sound at the beginning, so the word sounds approximately like yeg or yegh to an English speaker, though the exact Icelandic sound is a bit different.

A few pronunciation tips for the whole sentence:

• Stress is on the first syllable of each word
• Ég starts with a y sound
• nota is roughly NO-ta
• gagnagrunninn starts with a hard g/k-like sound and is stressed on the first syllable

So a very rough guide is:

YEG NO-ta GAK-na-grun-nin

That is only approximate, but it is a useful starting point.