Sy dui rigting aan.

Here Sy means she.

Afrikaans sy can also mean his in other contexts, but not in this sentence.

• Sy dui rigting aan. = She indicates direction.
• sy boek = his book

In this sentence, Sy is the subject pronoun.

Because the verb is aandui, which is a separable verb.

In a normal main clause, Afrikaans splits this kind of verb:

• the main verb part goes in the usual verb position
• the particle goes to the end

So:

• full verb: aandui
• in this sentence: dui ... aan

That is why you get Sy dui rigting aan.

Yes. It is one verb: aandui.

If you want to find it in a dictionary, look under aandui, not under aan.

This is very common with separable verbs in Afrikaans:

• sentence form: dui ... aan
• dictionary form: aandui

In the present tense, Afrikaans verbs usually do not change according to the subject.

So you get:

• Ek dui
• Jy dui
• Hy dui
• Sy dui

This is simpler than English, where we say I indicate but she indicates.

Rigting means direction.

In this sentence, it is the object of the verb. It tells you what she is indicating.

So the structure is:

• Sy = subject
• dui ... aan = verb
• rigting = object

Afrikaans does not always use an article where English would.

Here rigting aandui sounds natural as a general expression, something like indicate direction or show direction.

If you wanted to make it more specific, an article could appear in another sentence, for example:

• Sy dui die rigting na die dorp aan.

So the version without an article is normal here.

The pattern is:

Subject + finite verb + object + separable particle

So here:

• Sy = subject
• dui = finite verb
• rigting = object
• aan = separable particle

This is a very common Afrikaans word-order pattern in main clauses.

You would normally use the Afrikaans double negative:

Sy dui nie rigting aan nie.

In this sentence:

• the first nie comes after the finite verb dui
• the second nie comes at the end of the clause

That nie ... nie pattern is one of the most important parts of Afrikaans grammar.

When the verb is not sitting in the main-clause second position, it is usually written together as aandui.

For example:

• Ek weet dat sy rigting aandui.
• Sy kan rigting aandui.

So the split form dui ... aan is especially the main-clause pattern.