Hierdie handsak is myne, maar daardie jas is joune.

Because myne and joune are the Afrikaans forms for mine and yours.

• my = my
• jou = your
• myne = mine
• joune = yours

So:

• my handsak = my handbag
• Die handsak is myne = The handbag is mine

In this sentence, the speaker is not naming the owner before the noun; they are saying who the item belongs to after is, so Afrikaans uses the independent possessive forms myne and joune.

No, not in standard Afrikaans.

After is, you need the standalone possessive form:

• Dit is my handsak = It is my handbag
• Hierdie handsak is myne = This handbag is mine

And similarly:

• jou jas = your coat
• Daardie jas is joune = That coat is yours

So my and jou go before a noun, while myne and joune stand on their own.

In this sentence:

• hierdie = this
• daardie = that

So:

• Hierdie handsak = This handbag
• daardie jas = that coat

They are demonstratives, used to point something out.

No. That is an important difference from English.

In Afrikaans:

• hierdie can mean this or these
• daardie can mean that or those

The noun or the context tells you whether it is singular or plural.

For example:

• hierdie handsak = this handbag
• hierdie handsakke = these handbags

English changes the demonstrative, but Afrikaans usually does not.

Because hierdie and daardie already do that job of specifying the noun.

Afrikaans normally does not combine them with another article here.

So you say:

• hierdie handsak = this handbag
• daardie jas = that coat

Not:

• die hierdie handsak
• 'n daardie jas

The demonstrative itself is enough.

Yes, very much so.

The sentence follows a very familiar pattern:

• Hierdie handsak = subject
• is = linking verb
• myne = complement

Then the second clause works the same way:

• daardie jas
• is
• joune

And maar simply joins the two clauses.

So Afrikaans here is very close to English:

• This handbag is mine, but that coat is yours.

Here, maar means but.

It connects two contrasting ideas:

• this handbag belongs to me
• that coat belongs to you

So the sentence contrasts two possessions.

No.

Use:

• my handsak = my handbag
• jou jas = your coat

But:

• Die handsak is myne = The handbag is mine
• Die jas is joune = The coat is yours

So myne and joune do not normally go directly before a noun. They are used when the possessed noun is already understood or when the possessive stands alone.

A simple learner-friendly approximation is:

• jas ≈ yas
  The j in Afrikaans usually sounds like English y.
• myne ≈ MAY-nuh
• joune ≈ YOH-nuh

Also useful:

• hierdie ≈ HEER-dee
• daardie ≈ DAAR-dee

These are only rough guides, but they are good enough to help you start saying the sentence naturally.

No. Afrikaans does not have grammatical gender the way some other European languages do, and it does not use case endings like German.

So myne stays myne, and joune stays joune. They do not change because of handsak or jas.

That makes this part of Afrikaans simpler than in many other languages.

Yes.

• handsak literally looks like handbag, and that is exactly what it means.
• jas usually means coat or jacket, depending on context.

So both are common everyday nouns, and both are good vocabulary items to remember.