Die herstelkoste is hoog.

Die is the Afrikaans definite article, so here it means the.

A useful thing to remember: Afrikaans uses die for:

• singular nouns
• plural nouns
• all genders

So you do not have to learn different forms like the for one case and another article for a different gender.

By itself, die can be either singular or plural. The article does not change.

In this sentence, herstelkoste refers to repair costs, so the idea is naturally plural or collective in meaning. Afrikaans does not mark that difference on the article.

Because Afrikaans normally writes compound nouns as a single word.

So:

• herstel
  • koste → herstelkoste

This is very common in Afrikaans, just as in Dutch and German. English often uses two words where Afrikaans prefers one compound word.

It is made up of:

• herstel = repair, restoration, recovery
• koste = costs, expenses

Together, herstelkoste means repair costs.

In this sentence, herstel is understood in the sense of repair.

Because Afrikaans verbs do not change the way English verbs do in the present tense.

The verb wees = to be, but in the present tense you use is with all persons:

• ek is = I am
• jy is = you are
• hy is = he is
• ons is = we are
• hulle is = they are

So even if the meaning is plural in English, Afrikaans still uses is.

With things like costs, prices, rates, levels, Afrikaans very often uses hoog = high.

So:

• Die herstelkoste is hoog = The repair costs are high

Duur means expensive, and it is more often used for something being costly in general:

• Die motor is duur = The car is expensive
• Herstelwerk is duur = Repair work is expensive

So hoog is very natural with koste.

Because it comes after is, so it is being used as a predicate adjective.

In Afrikaans:

• after a linking verb like is, the adjective usually stays in its basic form
  
  • Die herstelkoste is hoog
• before a noun, the adjective often changes form
  
  • die hoë herstelkoste

So hoog stays hoog here because it comes after is.

Then hoog changes to hoë:

• die hoë herstelkoste = the high repair costs

Notice the spelling change:

• hoog → hoë

The two dots show that the vowels are pronounced separately.

Yes, in this simple main clause it is very similar:

• Die herstelkoste = subject
• is = verb
• hoog = adjective/complement

So the pattern is:

subject + is + adjective

That is one reason this sentence feels quite straightforward to English speakers.

A rough learner-friendly guide would be:

• die ≈ dee
• herstelkoste ≈ her-STEL-kos-tuh
• is ≈ iss
• hoog has a long oo sound, and the final g is a guttural Afrikaans sound, not an English hard g

A very rough approximation is:

dee her-STEL-kos-tuh iss hoagh

The hardest part for English speakers is usually the g in hoog. It is made in the throat, not like the g in go.

Yes. That is also a correct and natural way to express the same idea.

Compare:

• Die herstelkoste is hoog
• Die koste van herstel is hoog

The first version uses a compound noun, which Afrikaans likes very much. The second version is a slightly more unpacked structure, like the cost of repair or the costs of repair.

Both are grammatical.