Sy sal my dadelik bel wanneer die bus by die stasie aankom.

In this sentence, Sy is the subject pronoun, so it means she.

Afrikaans sy can be confusing because it can also mean his in other contexts:

• Sy sal my bel = She will call me
• sy bus = his bus

Here it clearly means she because it is followed by the verb sal and functions as the subject of the sentence.

Because my is the object of the verb bel here.

• Sy sal my bel = She will call me

Afrikaans my can mean either:

• me as an object pronoun
• my as a possessive

Compare:

• Sy sien my = She sees me
• my bus = my bus

So the meaning depends on its job in the sentence.

Sal is the future auxiliary, like will in English.

• Sy sal ... bel = She will ... call

It tells you the action is in the future. Afrikaans can sometimes use the present tense for future meaning if the context is clear, but sal makes the future explicit.

Because Afrikaans often uses this pattern with an auxiliary verb:

• finite verb in second position
• main verb in infinitive form later in the clause

So:

• Sy = subject
• sal = finite auxiliary in second position
• my dadelik = object and adverb
• bel = main verb at the end of the main clause

This is very normal in Afrikaans:

• Hy sal kom
• Ons kan dit doen
• Sy sal my bel

Dadelik means immediately, right away, or at once.

In this sentence it comes before the main verb bel:

• Sy sal my dadelik bel

That placement is natural in Afrikaans. Adverbs often come before the final infinitive in a clause with an auxiliary.

You may also hear slightly different word orders depending on emphasis, but this version is very standard.

Because wanneer introduces a subordinate clause, and in Afrikaans subordinate clauses normally send the verb to the end.

So:

• wanneer die bus by die stasie aankom

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

Compare:

• Main clause: Die bus kom by die stasie aan
• Subordinate clause: wanneer die bus by die stasie aankom

Yes. Aankom is a separable verb meaning arrive.

In a main clause, it often splits:

• Die bus kom by die stasie aan

But in an infinitive or at the end of a subordinate clause, it stays together:

• ... wanneer die bus by die stasie aankom

This is very common with Afrikaans separable verbs.

By here means something like at or to in the sense of reaching a place.

So:

• by die stasie aankom = arrive at the station

With locations like this, by is a normal choice in Afrikaans. It focuses on reaching that place or point.

Because die is the normal definite article in Afrikaans, and it does not change for gender the way articles do in some other languages.

So both are simply:

• die bus = the bus
• die stasie = the station

This is one thing that makes Afrikaans easier than languages with masculine, feminine, and neuter article systems.

Sometimes, yes, but the meaning may change slightly.

• wanneer = when
• sodra = as soon as
• as can sometimes mean when in certain contexts, but it can also mean if or as

In this sentence, wanneer is a clear and natural choice because it simply introduces the time clause: when the bus arrives at the station.

If you used sodra, the meaning would be more specifically:

• as soon as the bus arrives at the station

Yes. The time clause can come first:

• Wanneer die bus by die stasie aankom, sal sy my dadelik bel.

Notice what happens then:

• the subordinate clause still ends with aankom
• the main clause begins with sal, not sy sal

That is because Afrikaans keeps the finite verb in second position in the main clause. Since the whole wanneer-clause comes first, it counts as the first element, so sal comes next.