Akstursbannið byrjar í dag.

Because Icelandic uses compounds very freely.

Akstursbannið breaks down like this:

• aksturs- = driving / of driving
• bann = ban
• -ið = the

So the whole word means the driving ban.

English often writes similar ideas as multiple words, but Icelandic very often packs them into a single compound noun.

It is attached to the noun as a suffix: -ið.

So:

• bann = ban
• bannið = the ban

And in the full compound:

• akstursbann = driving ban
• akstursbannið = the driving ban

This is very normal in Icelandic. Instead of a separate word like English the, Icelandic often adds the definite article to the end of the noun.

The first part of many Icelandic compounds appears in a linking form, often the same as the genitive form.

Here:

• akstur = driving
• aksturs = of driving

So akstursbann is literally something like ban of driving, which English expresses as driving ban.

This pattern is very common in Icelandic compounds, and it is something learners get used to over time.

The head noun is bann, and bann is neuter.

In this sentence, akstursbannið is the subject, so it is in the nominative singular.

A useful rule: in Icelandic compounds, the last part usually determines the grammar of the whole word. So even though akstursbannið is long, its gender and inflection are controlled by bann.

Because the subject is singular.

The verb is byrja = to begin / to start. In the present tense:

• ég byrja = I begin
• þú byrjar = you begin
• hann/hún/það byrjar = he/she/it begins

Since akstursbannið is a singular subject, Icelandic uses byrjar.

A plural subject would take byrja, for example:

• Bönnin byrja í dag = The bans start today

No. Icelandic verbs agree with person and number, but not with gender.

So byrjar is used because the subject is third-person singular, not because it is neuter.

Whether the subject is masculine, feminine, or neuter, the third-person singular present form is still byrjar.

Í dag is a fixed expression meaning today.

Word by word, it is:

• í = in
• dag = day in a particular case form

But as a learner, the most useful thing is to memorize í dag as a whole expression meaning today.

It is extremely common, and you will hear it all the time.

Because dagur is the dictionary form, but here the noun appears in a different case inside the expression í dag.

So:

• dagur = day
• í dag = today

This is a good reminder that Icelandic nouns change form depending on case. In this particular expression, it is best learned as a set phrase.

Yes.

The sentence Akstursbannið byrjar í dag is a neutral way to say it.

But you can also say:

• Í dag byrjar akstursbannið.

That version puts more focus on today.

This is very natural in Icelandic. In main clauses, the finite verb usually stays in the second position, so when Í dag comes first, byrjar comes right after it.

A rough learner-friendly approximation is:

AK-sturs-ban-nið BIR-yar ee dag

A few useful notes:

• Stress is normally on the first syllable of each word.
• ð in -ið is like the th in this.
• í is pronounced like ee.
• The vowel in byrjar does not match English perfectly, but BIR-yar is a helpful approximation.

If you want to sound more natural, it is best to listen to native audio, because Icelandic consonants and vowels can be quite different from English ones.