Toe sy haar fout sien, het sy 'n posseël op die koevert geplak.

Here toe means when.

In this sentence, Toe sy haar fout sien, ... introduces a time clause: When she saw/noticed her mistake, ...

Afrikaans toe can also mean then in other contexts, but here it is a conjunction meaning when.

Because Toe sy haar fout sien is a subordinate clause.

In Afrikaans, subordinate clauses usually send the verb to the end. So:

• sy = she
• haar fout = her mistake
• sien = see/notice

Literally, the order is something like:

• When she her mistake saw

That is normal Afrikaans word order after a conjunction like toe.

This is a very common Afrikaans pattern after toe in past narration.

So Toe sy haar fout sien means When she saw/noticed her mistake, even though the verb looks like the present-tense form.

Afrikaans often uses this kind of toe + verb-final clause to describe a past event in a natural, story-like way. You could also sometimes see a form like Toe sy haar fout gesien het, but Toe sy haar fout sien is very normal and idiomatic.

Because the sentence begins with another clause, and that affects main-clause word order.

Afrikaans main clauses normally follow the verb-second rule. After the opening clause Toe sy haar fout sien, the finite verb of the main clause comes first:

• het sy 'n posseël op die koevert geplak

So the order is:

• first position: the whole opening clause
• second position: het
• then: sy

That is why you get het sy, not sy het.

Because the sentence starts with a subordinate clause:

• Toe sy haar fout sien,

and then moves to the main clause:

• het sy 'n posseël op die koevert geplak.

The comma marks that boundary, just like in English:

• When she saw her mistake, she stuck a stamp on the envelope.

In this sentence, both instances of sy mean she.

Afrikaans sy can also mean his in other contexts, which can confuse learners. For example:

• sy boek = his book

But here sy is clearly the subject pronoun:

• Toe sy ...
• het sy ...

So here it means she both times.

Because haar means her, while sy as a possessive means his.

So:

• haar fout = her mistake
• sy fout = his mistake

That is why haar fout is the correct choice here.

Literally, sien means see, but in this sentence it is better understood as notice or realize.

So Toe sy haar fout sien is naturally:

• When she noticed her mistake
• When she saw her mistake
• sometimes even When she realized her mistake

Afrikaans uses sien quite broadly, much like English see can sometimes mean understand or notice.

'n is the Afrikaans indefinite article, meaning a or an.

So:

• 'n posseël = a stamp

A few useful points:

• It is pronounced very weakly, like a schwa sound.
• It is written with an apostrophe.
• It stays lowercase even at the beginning of a sentence.

For example, at the start of a sentence you write:

• 'n Man loop daar.

not a capitalized version.

Posseël means postage stamp or simply stamp.

It is made from:

• pos = post/mail
• seël = seal/stamp

The ë shows that the vowels are pronounced separately, not merged into one sound. In Afrikaans, the dots often help show syllable division or pronunciation.

So the spelling tells you that posseël should be pronounced with a clear separate vowel sound in the second part.

Afrikaans very often expresses the past with het + past participle.

Here:

• het = auxiliary
• geplak = past participle of plak

So:

• het sy ... geplak = she stuck/pasted ...

This is the normal everyday way to talk about completed past actions in Afrikaans.

Because in a main clause with het, the participle usually goes to the end.

So the structure is:

• het
  • subject + other information + geplak

That gives:

• het sy 'n posseël op die koevert geplak

This is a standard Afrikaans pattern:

• Sy het die deur oopgemaak.
• Ek het die boek gelees.
• Hulle het koffie gedrink.

The auxiliary comes earlier, and the main verb form goes at the end.

Because op means on or onto, which fits the idea of putting a stamp on the surface of an envelope.

So:

• op die koevert = on the envelope

With plak, this is very natural Afrikaans for sticking or pasting something onto a surface.

Yes. Plak can cover several English ideas, depending on context:

• stick
• paste
• glue
• affix

In this sentence, the most natural English translations are things like:

• she stuck a stamp on the envelope
• she pasted a stamp onto the envelope
• she affixed a stamp to the envelope

So plak is a very useful everyday verb for attaching something to a surface.