Die onderwyser word kwaad wanneer die klas nie stil is nie.

In this sentence, word means becomes or gets.

So Die onderwyser word kwaad literally means The teacher becomes angry, which English usually expresses as The teacher gets angry.

This is a very common Afrikaans pattern:

• word moeg = get tired
• word bang = get scared
• word siek = get sick

Do not confuse this with English word. It is a verb in Afrikaans.

Because word kwaad focuses on the change of state: the teacher gets angry.

Compare:

• Die onderwyser is kwaad. = The teacher is angry.
• Die onderwyser word kwaad. = The teacher gets / becomes angry.

So is describes a state, while word describes becoming that way.

Kwaad usually means angry in a sentence like this.

So:

• Hy is kwaad. = He is angry.

Depending on context, kwaad can sometimes also relate to something being bad or harmful, but for learners the most important meaning here is angry.

Wanneer means when.

It introduces a clause explaining when the teacher gets angry:

• Die onderwyser word kwaad = The teacher gets angry
• wanneer die klas nie stil is nie = when the class is not quiet

So wanneer works much like English when.

After words like wanneer, Afrikaans often uses subordinate clause word order, where the conjugated verb goes later in the clause.

Main clause:

• Die onderwyser word kwaad.

Subordinate clause:

• wanneer die klas nie stil is nie

Notice that is comes near the end of the clause. This is normal in Afrikaans subordinate clauses introduced by words like:

• wanneer = when
• omdat = because
• as = if / when
• dat = that

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

Afrikaans usually uses double negation.

So nie ... nie is the normal way to say not in many sentences.

Here:

• die klas nie stil is nie = the class is not quiet

The first nie usually comes before the part being negated, and the second nie comes near the end of the clause.

This is one of the most distinctive features of Afrikaans.

In standard Afrikaans, the second nie usually closes the negative clause.

So in:

• wanneer die klas nie stil is nie

the final nie marks the end of the negation.

English speakers often forget this second nie, but in standard Afrikaans it is normally required.

Die klas literally means the class, but it can refer to the group of students as a whole.

So die klas nie stil is nie means the class is not quiet, meaning the students are making noise.

English does the same thing:

• The class is noisy
• The class is not quiet

So klas can refer to the group, not just the room or the lesson.

Because die is the definite article the in Afrikaans.

Afrikaans does not have different words for the based on gender, unlike languages such as German or Dutch. So:

• die onderwyser = the teacher
• die klas = the class

The same article is used for all singular nouns and also for plural nouns.

Traditionally, onderwyser is teacher, and onderwyseres can mean female teacher.

In modern usage, however, onderwyser is often used generally unless there is a reason to specify gender.

So in many contexts, die onderwyser can simply be understood as the teacher.

Yes, raak kwaad is also possible in Afrikaans and also means get angry.

Compare:

• Die onderwyser word kwaad
• Die onderwyser raak kwaad

Both are natural, though word kwaad is very straightforward and common for learners to understand as becomes angry.

There actually is one: is.

In die klas nie stil is nie, the word is is the verb is / are. It just appears later because of subordinate clause word order.

If you put it in a main clause, it looks more familiar:

• Die klas is nie stil nie. = The class is not quiet.

After wanneer, the verb moves:

• wanneer die klas nie stil is nie

So the verb is still there; it is just in a different position.

No. Even though they look similar, stil in Afrikaans means quiet or silent, not still in the sense of not moving.

Examples:

• Wees stil! = Be quiet!
• Die kinders is stil. = The children are quiet.

This is a false friend English speakers should watch out for.

Almost, but not perfectly.

A very literal breakdown is:

• Die onderwyser = the teacher
• word = becomes / gets
• kwaad = angry
• wanneer = when
• die klas = the class
• nie ... nie = not
• stil = quiet
• is = is

So the literal structure is something like:

The teacher gets angry when the class not quiet is not.

That sounds wrong in English, but it shows two important Afrikaans features:

• subordinate clause word order
• double negation

A natural English translation is the one already given to the learner.