Ég ætla ekki þangað aftur í þessari viku.

Ætla often means to intend, to plan, or to be going to.

In this sentence, it expresses the speaker’s intention or plan. So it is not just a plain statement about the future; it carries the idea of not planning or not intending to do something.

A learner will often meet ætla in sentences like:

• Ég ætla að fara. — I intend to go.
• Við ætlum að borða. — We’re going to eat.

So here, ætla is the key word showing intention.

That is a very natural question, because learners are often taught ætla að + infinitive, such as ætla að fara.

A fuller version of this sentence could be:

• Ég ætla ekki að fara þangað aftur í þessari viku.

But Icelandic can omit the motion verb when the destination already makes the meaning obvious. Since þangað already tells you the idea is going there, the verb fara can be understood without being said.

So this shorter version is natural, especially in everyday language.

Þangað is a directional adverb. It means to there or there in the sense of going there.

This is different from:

• þar — there, at that place
• þangað — to there, to that place
• þaðan — from there

So Icelandic makes a distinction that English often does not make clearly.

Compare:

• Ég er þar. — I am there.
• Ég fer þangað. — I go there.
• Ég kem þaðan. — I come from there.

Because Icelandic normally puts the finite verb early in the sentence, and ekki usually comes after that verb.

So:

• Ég ætla ekki ...

is the normal order.

For an English speaker, it may feel like not should go somewhere else, but in Icelandic ekki very often follows the finite verb in a main clause.

This is connected to Icelandic’s verb-second pattern. In a neutral sentence, the subject comes first, then the finite verb, then ekki.

Here í takes the dative, because the phrase means within this week or during this week.

So:

• þessari viku = dative singular

The important word is þessari, which is the dative feminine singular form of þessi.

A simple way to think about it is:

• í + dative is often used for location or time within something
• í + accusative is often used for movement into something

In this sentence, the phrase is a time expression, not movement into the week, so the dative is used.

Þessari is the dative singular feminine form of þessi (this).

It has to agree with viku, because vika is:

• feminine
• singular
• here, in the dative

So the matching form is:

• þessi → nominative feminine singular
• þessa → accusative feminine singular
• þessari → dative feminine singular

That agreement is very important in Icelandic grammar.

In this sentence, viku is dative singular, because of í þessari viku.

But the reason it may look confusing is that vika has the same form viku in more than one case. So the noun itself does not clearly show the difference here.

That is why þessari is especially helpful: it shows you that the whole phrase is dative.

So even though viku could also appear in other case contexts, here the phrase is definitely dative.

It can mean either, depending on context.

In Icelandic, aftur is used for both ideas:

• again
• back

So þangað aftur can mean:

• there again
• back there

English often separates these meanings more than Icelandic does. In this sentence, the intended English translation will tell you which one sounds best, but grammatically Icelandic aftur can cover both.

The order in the sentence is the most natural, neutral one.

• þangað aftur sounds like there again / back there
• aftur þangað is possible in some contexts, but it can sound more marked or emphasize again

So the given order is the one a learner should probably copy first.

Icelandic word order is somewhat flexible, but not all possible orders sound equally natural in an ordinary statement.

Yes. Icelandic allows different word orders for focus or emphasis.

For example, you could front þangað:

• Þangað ætla ég ekki aftur í þessari viku.

That gives extra emphasis to there.

But the original sentence is the most neutral everyday version:

• Ég ætla ekki þangað aftur í þessari viku.

So if you are learning, the original order is a good default pattern to remember.