Bíllinn kemur í skoðunarstofuna í þann mund sem hún opnar.

Bíllinn means the car.

In Icelandic, the definite article (the) is usually attached to the end of the noun instead of being a separate word. So:

• bíll = car
• bíllinn = the car

This is very common in Icelandic. English uses a separate word (the car), but Icelandic often uses a suffix.

Kemur is the present tense of koma (to come).

So:

• að koma = to come
• kemur = comes / is coming

In this sentence, Bíllinn kemur ... means The car comes / is coming ...

Icelandic often uses the simple present in places where English might also use is coming, depending on context.

Here í means into / to.

The preposition í can take different cases depending on whether there is:

• location (being in a place) → usually dative
• movement toward/into a place → usually accusative

Here the car is moving to/into the inspection station, so Icelandic uses the accusative:

• í skoðunarstofuna

Compare the idea:

• Bíllinn er í skoðunarstofunni = The car is in the inspection station
• Bíllinn kemur í skoðunarstofuna = The car comes into/to the inspection station

So the case changes because the meaning changes.

It is a compound noun plus the definite article and case ending.

You can break it down like this:

• skoðun = inspection
• stofa = room / office / station
• skoðunarstofa = literally something like inspection office/station
• skoðunarstofuna = the inspection station in the accusative singular

The -ar- in the middle comes from the genitive form of skoðun, which is common in Icelandic compounds.

So this is a very typical Icelandic compound noun structure.

Because this sentence needs the accusative, not the dative.

With í:

• movement into/to something → accusative
• location in something → dative

So:

• í skoðunarstofuna = into/to the inspection station
• í skoðunarstofunni = in the inspection station

Since the car is arriving there, -una is the correct form.

This is an idiomatic expression meaning:

• just as
• at the moment when
• right when

So:

• í þann mund sem hún opnar = just as it opens

This is not something you would usually translate word-for-word in normal English. It is better to learn it as a fixed phrase.

This is part of the fixed expression í þann mund (sem).

The word mund here means moment or point in time, and þann is the masculine accusative singular form of sá (that).

So literally it is something like in that moment, but in real usage the whole phrase means just as / at the very moment when.

Because it is an idiom, learners usually do best to memorize the whole phrase:

• í þann mund sem ...

rather than trying to build it from scratch each time.

Sem means that / which / when / as, depending on context.

In this sentence, it links the time expression to the clause that follows:

• í þann mund sem hún opnar

Here sem is best understood as when or as:

• just as she/it opens

So sem introduces the subordinate clause.

Hún refers to skoðunarstofan.

Even though English would normally say it opens, Icelandic uses pronouns that match the grammatical gender of the noun:

• skoðunarstofa is feminine
• so the pronoun is hún (she grammatically, but often translated as it in English)

So in this sentence, hún opnar means it opens, referring to the inspection station.

This is a very important difference from English: Icelandic pronouns often follow grammatical gender, not natural gender.

Formally, yes, hún is the same word that also means she. But here it should be understood as it, because it refers to a feminine noun, not a female person.

So:

• hún opnar = it opens

This is normal in Icelandic. A feminine noun can be referred to with hún, a masculine noun with hann, and a neuter noun with það.

Good question. Opna can be used both:

• transitively: to open something
• intransitively: to open

So:

• Hún opnar dyrnar. = She opens the door.
• Verslunin opnar klukkan tíu. = The store opens at ten.

In your sentence, hún opnar means it opens. No object is needed.

The basic structure is:

• Bíllinn kemur í skoðunarstofuna
• í þann mund sem hún opnar

So first you get the main clause:

• The car comes to the inspection station

Then a time expression:

• just as it opens

A more literal breakdown is:

• Bíllinn = the car
• kemur = comes
• í skoðunarstofuna = into/to the inspection station
• í þann mund sem = just as / at the moment when
• hún opnar = it opens

Yes. That is a very natural English translation.

Although koma basically means come, English often prefers arrive in sentences like this. So depending on context, these can both work well:

• The car comes to the inspection station just as it opens.
• The car arrives at the inspection station just as it opens.

The second one may sound more natural in English, even though the Icelandic verb is still simply koma.

It is a normal idiomatic expression, but it can sound a bit more literary or formal than simply using a more basic time word.

It is perfectly understandable and correct, but in everyday speech people might also use simpler ways to express similar ideas, depending on context.

For a learner, the important thing is to recognize it as a set phrase meaning:

• just as
• right when
• at the moment when

Here hún is in the nominative, because it is the subject of opnar.

In the clause:

• hún opnar

the inspection station is the thing doing the opening, so it is the subject, and Icelandic uses the nominative for subjects.

Because Icelandic pronouns are strongly tied to grammatical gender.

English usually uses it for things. Icelandic usually does not do that in the same way. Instead, it uses:

• hann for masculine nouns
• hún for feminine nouns
• það for neuter nouns

Since skoðunarstofa is feminine, Icelandic naturally says hún.

So this is one of those places where a literal word-for-word translation can be misleading. Grammatically, Icelandic says hún, but idiomatic English says it.