Sy sê jammer, omdat my boek nog by haar huis is.

Because they do different jobs in the sentence.

• sy = she when it is the subject
• haar = her when it is the object or comes after a preposition

So in:

• Sy sê jammer = She says sorry
• by haar huis = at her house / at her place

After the preposition by, Afrikaans uses haar, not sy.

Sê jammer literally means say sorry, and in normal English it often corresponds to be sorry or apologize.

So Sy sê jammer can be understood as:

• She says sorry
• She is sorry
• She apologizes

In Afrikaans, jammer is very commonly used for apologizing or expressing regret.

Omdat means because.

It introduces the reason for the apology:

• Sy sê jammer = the main statement
• omdat my boek nog by haar huis is = the reason

So omdat starts a subordinate clause, which is important because it changes the word order.

Because omdat introduces a subordinate clause, and in Afrikaans subordinate clauses usually send the conjugated verb to the end.

Compare:

• Main clause: My boek is nog by haar huis.
• Subordinate clause: ... omdat my boek nog by haar huis is.

This is one of the most important word-order patterns in Afrikaans.

Here nog means still.

So:

• my boek nog by haar huis is = my book is still at her house

It shows that the situation has not changed yet. The book remains there.

Be careful, because nog can mean different things in different contexts, such as another, yet, or more, but here it clearly means still.

By haar huis is the normal way to say at her house / at her place.

• by haar huis = at her house, at her home, at her place
• in haar huis = inside her house

So by is often used when talking about being at someone's place in a general sense, not necessarily emphasizing the inside of the building.

Yes, haar huis means her house.

Afrikaans uses haar as a possessive form too:

• haar huis = her house
• haar boek = her book

So haar can mean:

• her after a preposition: by haar
• her as a possessive: haar huis

In this sentence, both happen together in by haar huis, which literally looks like at her house.

Because Afrikaans uses my for my before a noun.

• my boek = my book
• my huis = my house

Afrikaans does not use mine before a noun the way English distinguishes my book and mine. If the noun is not stated, Afrikaans would usually phrase it differently, for example:

• Die boek is myne = The book is mine

But before a noun, you use my.

Yes. You can also put the omdat clause first:

• Omdat my boek nog by haar huis is, sê sy jammer.

That is also correct.

Notice that after the subordinate clause comes sê sy, not sy sê. In Afrikaans, when something else comes first, the finite verb usually stays in second position in the main clause.

So both are correct:

• Sy sê jammer, omdat my boek nog by haar huis is.
• Omdat my boek nog by haar huis is, sê sy jammer.

Because Afrikaans usually separates the main clause and the subordinate clause with a comma.

Here:

• main clause: Sy sê jammer
• subordinate clause: omdat my boek nog by haar huis is

So the comma helps mark the boundary between them. This is very common in written Afrikaans.

Yes. Jammer is a very flexible word in Afrikaans.

Depending on context, it can mean things like:

• sorry
• sad
• a pity
• unfortunate

For example:

• Ek is jammer. = I am sorry.
• Dis jammer. = That is a pity.

In this sentence, though, sê jammer clearly means apologizing.

Because my boek already has a determiner: my.

In Afrikaans, as in English, you normally do not combine my with the:

• my boek = my book
• not die my boek

So the possession word my already does the job of identifying the noun.

A simple way to break it down is:

• Sy = subject
• sê = verb
• jammer = expression/complement
• omdat = conjunction introducing the reason
• my boek = subject of the subordinate clause
• nog = adverb
• by haar huis = place expression
• is = verb at the end of the subordinate clause

So the pattern is:

Main clause + comma + subordinate clause

And inside the subordinate clause, the verb goes to the end because of omdat.