Í tölvupóstinum stendur að fundurinn byrjar klukkan níu.

Because í means in, and here it describes location, so it takes the dative case.

• tölvupóstur = email in the nominative
• í tölvupóstinum = in the email

The ending -inum shows two things at once:

1. dative singular
2. definite article = the

So:

• tölvupóstur = an email
• tölvupósturinn = the email
• í tölvupóstinum = in the email

A useful rule:

• í + dative for being in a place
• í + accusative for movement into a place

Here nothing is moving, so dative is used.

The verb standa literally means to stand, but Icelandic often uses standa when talking about written text.

So Í tölvupóstinum stendur ... means something like:

• In the email, it says ...
• more literally, In the email, it stands written ...

This is a very common Icelandic way to refer to what is written in a text.

You may also see similar expressions with other written sources:

• Í bókinni stendur ... = In the book it says ...
• Í bréfinu stendur ... = In the letter it says ...

að here means that and introduces a subordinate clause.

So the structure is:

• Í tölvupóstinum stendur = The email says
• að fundurinn byrjar klukkan níu = that the meeting starts at nine

This is very similar to English:

• It says that the meeting starts at nine.

In everyday English, that is often omitted, but in Icelandic að is very commonly included.

fundur means meeting, while fundurinn means the meeting.

Icelandic usually adds the definite article to the end of the noun instead of using a separate word like English the.

So:

• fundur = a meeting
• fundurinn = the meeting

Here the sentence is talking about a specific meeting already known from context, so fundurinn is used.

Also, fundurinn is in the nominative case because it is the subject of byrjar.

Because Icelandic often uses the present tense for scheduled or planned future events, just like English does.

Compare:

• The meeting starts at nine tomorrow.
• fundurinn byrjar klukkan níu

So byrjar literally means starts / is starting, but in context it naturally refers to a future scheduled event.

This is very common with timetables, appointments, transport, meetings, and similar things.

klukkan níu means at nine o’clock.

This is the normal Icelandic way to give the time when something happens.

• klukkan is the form used in time expressions like at one, at two, at nine
• níu = nine

Examples:

• klukkan eitt = at one o’clock
• klukkan þrjú = at three o’clock
• klukkan níu = at nine o’clock

Learners often notice that klukkan looks like the clock. Historically it is related to that, but in modern usage you can mostly just learn klukkan + time as a fixed pattern meaning at ... o’clock.

This is because Icelandic is generally a verb-second language in main clauses.

That means the finite verb usually comes in the second position, not necessarily after the subject.

Here the sentence begins with the prepositional phrase:

• Í tölvupóstinum = In the email

Since that takes first position, the verb comes next:

• Í tölvupóstinum stendur ...

This is normal Icelandic word order.

Compare:

• Fundurinn byrjar klukkan níu. = The meeting starts at nine.
• Í tölvupóstinum stendur að fundurinn byrjar klukkan níu. = In the email it says that the meeting starts at nine.

So the first element can change, but the finite verb still tends to stay in second position in a main clause.

Because Icelandic often does not need a dummy subject like English it in expressions of this kind.

English says:

• In the email, it says that ...

But Icelandic can simply say:

• Í tölvupóstinum stendur að ...

There is no separate word for it here. The meaning is understood from the context and the structure of the sentence.

This is one of those places where English requires a subject more often than Icelandic does.

Yes. tölvupóstur is a compound noun.

It is built from:

• tölva = computer
• póstur = mail, post

So tölvupóstur literally means something like computer-mail, which is the Icelandic word for email.

Compound nouns are extremely common in Icelandic, and learning to spot the parts can really help with vocabulary.

Yes, that would also be possible, but it means something slightly different in focus.

• Í tölvupóstinum stendur að fundurinn byrjar klukkan níu.

  • Focuses on what is written in the email.
  • Very natural when reporting written information.

• Fundurinn byrjar klukkan níu samkvæmt tölvupóstinum.

  • Means The meeting starts at nine according to the email.
  • Focuses more directly on the meeting time, with according to the email added as a source.

So the original sentence is especially natural when you want to quote or summarize what the email says.

Then you would use fundur instead of fundurinn:

• Í tölvupóstinum stendur að fundur byrjar klukkan níu.

But this is less natural in many contexts, because usually a meeting mentioned in an email is a specific one, so the meeting is more likely than a meeting.

That is why fundurinn is the most natural form in the original sentence.