Við ætlum að láta setja nýjan lampa í ganginn.

Við means we.

ætlum is the 1st person plural present of ætla, which often means to intend, to plan, or in many contexts to be going to.

With að + infinitive, it introduces the action being planned:

• Við ætlum að... = We intend to... / We are going to...

So this part sets up the idea that we are planning whatever follows.

Because the að belongs with ætla.

The pattern is:

• ætla að + infinitive

So here we get:

• ætlum að láta...

Then láta forms its own construction with another infinitive:

• láta + infinitive

So:

• láta setja = have [someone] install / cause [someone] to install

That is why Icelandic says:

• Við ætlum að láta setja...

and not something like að láta að setja.

Láta can mean several related things, including let, make, have, or cause to depending on context.

In this sentence, it is a causative verb. That means the subject is not necessarily doing the action personally; instead, the subject is arranging for it to happen.

So:

• láta setja = have installed
• more literally: cause [someone] to install

This is very similar to English sentences like:

• We’re going to have a new lamp installed.

So láta here does not mean simple permission (let). It means something closer to have something done.

The sentence does not say.

That is completely normal with this construction. Icelandic often leaves the actual doer unstated when the important idea is that someone arranges for the job to be done.

So the meaning is something like:

• We are going to have a new lamp installed in the hallway.

This suggests that another person — maybe an electrician or handyman — will do the work, but the sentence does not name them.

If you wanted to name the person, you could add them, for example:

• Við ætlum að láta rafvirkja setja nýjan lampa í ganginn.
• We’re going to have an electrician install a new lamp in the hallway.

Because nýjan lampa is the direct object of setja.

The verb setja takes an object in the accusative, so both the noun and the adjective have to appear in accusative form.

Here is the agreement:

• lampi = lamp (nominative singular)
• lampa = lamp (accusative singular)

And for the adjective:

• nýr = nominative masculine singular
• nýjan = accusative masculine singular

So:

• nýjan lampa = a new lamp as the object of the verb

The adjective and noun must match in:

• gender
• number
• case

Since lampi is masculine singular accusative here, the adjective becomes nýjan.

This is a very common Icelandic question.

With prepositions like í, Icelandic often distinguishes between:

• movement/placement into a place → accusative
• location in a place → dative

Here the verb is setja, which involves putting/placing/installing something into a location. Because of that, accusative is natural:

• í ganginn = into the hallway / in the hallway in the sense of placement there

By contrast, if you were just describing where something already is, you would usually use dative:

• Lampinn er í ganginum.
• The lamp is in the hallway.

So even though English may simply say in the hallway, Icelandic sees this as a placement action, and that is why ganginn is used here.

Because they play different roles in the sentence.

• ganginn = the hallway
• nýjan lampa = a new lamp

In many contexts, the hallway is a specific, known place — for example, the hallway in a particular home — so the definite form is natural.

Meanwhile, the lamp is being introduced as new information, so the indefinite form is natural:

• a new lamp

If you were talking about a specific lamp already known to both speaker and listener, you could make that definite too:

• nýja lampann = the new lamp

So the choice between definite and indefinite is about whether the thing is being treated as specific/known or new/not previously identified.

That is the Icelandic suffixed definite article.

Instead of always using a separate word like English the, Icelandic often adds the definite article to the end of the noun.

So:

• gangur = hallway (dictionary form)
• ganginn = the hallway in the accusative singular

This is very common in Icelandic. The exact ending changes depending on gender, number, and case.

So in this sentence, ganginn already includes the meaning of the hallway.

Yes. This is the most neutral and natural order.

The sentence is structured roughly like this:

• Við = subject
• ætlum = finite verb
• að láta setja... = infinitive phrase
• nýjan lampa = object
• í ganginn = destination/location phrase

So the full sentence follows a very standard pattern:

• Subject + finite verb + infinitive construction + object + prepositional phrase

Icelandic word order can be moved around for emphasis, but this version is straightforward and unmarked.

For example, you could front something for emphasis:

• Nýjan lampa ætlum við að láta setja í ganginn.

That would emphasize new lamp, but the original sentence is the plain, neutral way to say it.