Hún skutlaði systur sinni í skólann áður en hún fór í vinnuna.

Skutlaði is the past tense of að skutla.

In this sentence, að skutla einhverjum means to give someone a ride or to drop someone off. It is a very natural everyday verb, often used for short, practical trips.

So Hún skutlaði systur sinni í skólann means something like:

• She gave her sister a ride to school
• She dropped her sister off at school

It is a bit more specific and colloquial than just keyrði (drove).

Because sister is not the subject of the sentence. It is the person being driven, and with að skutla that person is normally in the dative case.

So:

• systir = nominative singular, sister as a subject
• systur = a form used for several other cases, including dative singular

The word sinni helps you see the case clearly:

• sinni = feminine singular dative of sinn

So systur sinni means to her own sister / her sister in the dative.

A useful pattern is:

• að skutla einhverjum = to give someone a ride

Because sinni is a reflexive possessive. Icelandic uses sinn / sín / sitt when the possessor is the same as the subject of the clause.

Here the subject is hún (she), so:

• systur sinni = her own sister / her sister (where her refers back to the subject)

If you used hennar, it would usually suggest someone else’s sister, not the subject’s own sister.

So the contrast is roughly:

• Hún skutlaði systur sinni... = She drove her own sister...
• Hún skutlaði systur hennar... = She drove her sister (someone else’s sister)

Because the sentence describes movement toward a destination.

In Icelandic, with í:

• í + accusative usually shows motion into / to
• í + dative usually shows location in

So:

• í skólann = to school / into the school
• í skólanum = in the school

Since she is taking her sister to school, Icelandic uses accusative:

• í skólann

For the same basic reason: it shows movement toward work.

• fór í vinnuna = went to work
• var í vinnunni = was at work / in the workplace

Also, Icelandic often uses the definite form in places where English does not. So English says to work, but Icelandic very naturally says í vinnuna.

Likewise:

• í skólann = to school
• í vinnuna = to work

This does not necessarily sound unusually specific in Icelandic.

Áður en means before.

It introduces a clause:

• áður en hún fór í vinnuna = before she went to work

So the structure is:

• main action: Hún skutlaði systur sinni í skólann
• time clause: áður en hún fór í vinnuna

Literally, the whole sentence is:

• She drove her sister to school before she went to work

Normally, no. Icelandic usually needs an explicit subject in a finite clause.

So after áður en, you still need:

• hún fór í vinnuna

not just:

• áður en fór í vinnuna ✗

That second hún is the subject of the subordinate clause.

Grammatically, it can be ambiguous, because both possible people are feminine singular:

• the woman who drove
• the sister

So áður en hún fór í vinnuna could, in isolation, be interpreted as before she went to work, where she could refer to either one.

In normal reading, many people will assume it refers to the main subject, the woman who did the driving. But context is what really settles it.

If a speaker wanted to avoid ambiguity, they could rephrase the sentence more clearly.

Both are in the past tense.

• skutlaði = past tense of að skutla
• fór = past tense of að fara (to go)

They are formed differently because Icelandic has different verb patterns:

• að skutla is a regular/weak verb → skutlaði
• að fara is an irregular/strong verb → fór

So the sentence is describing two past actions:

1. she drove her sister to school
2. she went to work

Because áður en introduces a subordinate clause, and the clause keeps normal subject-verb order:

• áður en hún fór í vinnuna

That is different from what happens when a time expression is moved to the front of a main clause. For example, you can also say:

• Áður en hún fór í vinnuna skutlaði hún systur sinni í skólann.

Here the whole before-clause comes first, and then the main clause follows. In that version, Icelandic shows normal main-clause word-order behavior, with the finite verb skutlaði coming before the subject hún.

So the original sentence is actually the simpler order for a learner to recognize:

• main clause first
• subordinate clause second

Because some Icelandic nouns have forms that overlap.

For systir (sister), the singular forms are partly identical:

• nominative: systir
• accusative: systur
• dative: systur
• genitive: systur

So just looking at systur alone does not tell you the case. In this sentence, the case becomes clear because of:

• the verb pattern að skutla einhverjum (dative)
• the reflexive possessive sinni, which is clearly dative feminine singular

So systur sinni is clearly dative, even though systur by itself is ambiguous.

Yes. A very natural alternative is:

• Áður en hún fór í vinnuna skutlaði hún systur sinni í skólann.

This means the same thing.

The main difference is emphasis and word order:

• original: first tells you what she did, then when
• alternative: first tells you the time frame, then the main action

Both are good Icelandic.