Hún skiptir um bleyju á skiptiborðinu áður en við förum út.

In Icelandic, skipta on its own often means divide, exchange, matter, or switch, depending on context. But the fixed expression skipta um commonly means change or change out.

So:

• skipta um bleyju = change a diaper
• literally, it is something like change out a diaper

This is a very common verb combination, and it is best learned as a unit: skipta um + accusative noun.

Because skipta um takes the accusative case, and bleyja changes form in the accusative singular.

The noun is:

• nominative: bleyja = a diaper
• accusative: bleyju

So:

• Hún skiptir um bleyju = She is changing a diaper

This is a very common thing in Icelandic: the noun changes form depending on its grammatical role.

In normal usage, skipta um bleyju usually means change the diaper in the everyday sense, even though Icelandic does not have an article here.

So although the noun is technically indefinite in form, the phrase is commonly understood as the usual activity of changing a baby’s diaper.

In context, English often uses the or a possessive, but Icelandic often does not need that:

• Hún skiptir um bleyju = She is changing the diaper / changing a diaper

The exact English wording depends on context.

This means on the changing table.

The noun is skiptiborð:

• skipti relates to changing
• borð means table

The form skiptiborðinu is:

• singular
• definite = the changing table
• dative case

So:

• á skiptiborði = on a changing table
• á skiptiborðinu = on the changing table

Because after á, Icelandic uses:

• dative for location = on, in, at
• accusative for motion toward something

Here the meaning is location, not movement:

• á skiptiborðinu = on the changing table

She is already there, or the action happens there. There is no idea of moving onto it.

Compare:

• Hún er á skiptiborðinu = She is on the changing table
• Hún leggur barnið á skiptiborðið = She lays the baby onto the changing table

In the second example, there is movement onto the table, so accusative is used.

Áður en means before in the sense of before something happens.

It introduces a clause:

• áður en við förum út = before we go out

You can think of it as:

• áður = earlier / before
• en = than / when introducing this kind of comparison-like clause

Together they work like a fixed expression: áður en = before.

Because áður en is followed by a full clause, not just an infinitive.

So Icelandic says:

• áður en við förum út = before we go out

This has:

• subject: við = we
• finite verb: förum = go

English also usually uses a full clause here: before we go out.

If you used að fara út, that would be an infinitive phrase, and that is not what this structure normally wants.

That is normal in Icelandic. The present tense is often used for future meaning when the time is clear from context.

So:

• áður en við förum út literally looks like before we go out
• but in context it can mean before we go out later

English does the same thing:

• She changes the diaper before we go out

Even if going out is still in the future, the present tense is used in the subordinate clause.

Út means out and completes the idea of going out.

So:

• fara = go, travel
• fara út = go out

This is very similar to English, where go and go out do not mean exactly the same thing.

In the sentence:

• við förum út = we go out / we are going out

Yes. Hún means she, but it can also refer to any noun that is grammatically feminine.

So depending on context, hún could refer to:

• a woman or girl
• a feminine-gender noun, such as an object or animal already mentioned

In this sentence, though, a learner will usually understand it as she unless context says otherwise.

It could be either, depending on context.

Hún skiptir um bleyju á skiptiborðinu áður en við förum út can mean:

• something happening now or around now: She’s changing the diaper on the changing table before we go out
• a regular pattern: She changes the diaper on the changing table before we go out

Icelandic present tense often covers both simple present and present progressive meanings that English separates.

So the exact translation depends on the situation.