Hendes forklaring var tydelig, så jeg forstod teksten bedre.

This is a very common Danish question.

Danish uses:

• sin/sit/sine for a reflexive possessor, when the owner is the subject of the same clause
• hans/hendes/deres when the owner is not the subject of that clause

In Hendes forklaring var tydelig, the grammatical subject is forklaring (explanation), not the woman. So the reflexive form sin cannot be used here.

So:

• hendes forklaring = her explanation
• sin forklaring would only work if the subject were the person who owns the explanation

For example:

• Hun forklarede teksten med sin forklaring. = She explained the text with her own explanation.

But in your sentence, hendes is the correct choice.

Hendes is a possessive determiner. It means her in the sense of ownership.

Some related Danish possessives are:

• min = my
• din = your
• hans = his
• hendes = her
• vores = our
• jeres = your
• deres = their / your (formal)

Unlike some adjectives, hendes does not change form here.

Forklaring is the indefinite singular form: an explanation / explanation.

Forklaringen is the definite singular form: the explanation.

Danish often uses a possessive instead of the definite ending. So:

• hendes forklaring = her explanation
• not hendes forklaringen

This is similar to English, where we say her explanation, not her the explanation.

Because forklaring is a common-gender singular noun: en forklaring.

When an adjective is used after var as a predicate adjective, it still agrees with number and, in the singular, with gender:

• en forklaring var tydelig
• et svar var tydeligt
• forklaringerne var tydelige

So in your sentence:

• forklaring is a common-gender noun
• therefore the adjective is tydelig

If the noun were neuter, you would use -t:

• Et ord var tydeligt.

Var is the past tense of at være (to be).

So:

• er = is / are
• var = was / were

In the sentence:

• Hendes forklaring var tydelig
• Her explanation was clear

This is one of the most common irregular verbs in Danish, so it is worth memorizing:

• at være
• er
• var
• har været

Because så here connects two main clauses:

1. Hendes forklaring var tydelig
2. jeg forstod teksten bedre

In standard Danish punctuation, a comma is normally used between coordinated main clauses like this.

So the comma helps show the structure:

• Her explanation was clear, so I understood the text better.

Here så means so, in the sense of therefore / as a result.

Danish så can have several uses depending on context, for example:

• så = so / therefore
• så = then
• så ... at = so ... that

In your sentence, it clearly shows result:

• Hendes forklaring var tydelig, så jeg forstod teksten bedre.
• Her explanation was clear, so I understood the text better.

Because så here is a conjunction joining two clauses, not an adverb placed at the front of a clause.

After a coordinating conjunction like this, Danish keeps normal main-clause word order:

• så jeg forstod teksten bedre

If så were being used as a sentence adverb meaning something like then/so, placed first in the clause, you could get inversion:

• Så forstod jeg teksten bedre.
• Then I understood the text better.

So both patterns exist, but they mean/behave slightly differently:

• ..., så jeg forstod ... = ..., so I understood ...
• Så forstod jeg ... = Then/so I understood ...

Yes. Forstod is the past tense of at forstå (to understand).

This verb is irregular:

• at forstå = to understand
• forstår = understand / understands
• forstod = understood
• har forstået = have/has understood

So:

• jeg forstår = I understand
• jeg forstod = I understood

Because the sentence is in the past, Danish uses forstod.

Teksten is the definite form, meaning the text.

Forms:

• en tekst = a text
• teksten = the text

In this sentence, it refers to a specific text that the speaker understood better, so the definite form is natural.

Because bedre is the comparative form of godt / god in this meaning.

Just like English has:

• good
• better

Danish has:

• god = good
• godt = well / good (neuter/adverb form depending on use)
• bedre = better
• bedst = best

After forstå, Danish commonly uses bedre to mean better:

• Jeg forstod teksten bedre.
• I understood the text better.

Using mere godt would sound unnatural here.

It modifies the idea of understanding, not the text itself.

So:

• jeg forstod teksten bedre
• literally: I understood the text better

It does not mean that the text became better. It means the speaker’s understanding improved.

No, Danish normally needs the subject to be stated clearly in each finite clause.

So after så, the second clause needs its own subject:

• så jeg forstod teksten bedre

You cannot normally omit jeg here the way some languages might.

You would mainly change the verbs:

• Hendes forklaring er tydelig, så jeg forstår teksten bedre.

Changes:

• var → er
• forstod → forstår

Everything else can stay the same.

Here tydelig means clear in the sense of easy to follow or understand.

It can also mean distinct or obvious depending on context.

In this sentence:

• Hendes forklaring var tydelig
• means her explanation was presented clearly

So it describes the quality of the explanation, not just loudness or visibility.

Usually forklaring most directly means explanation.

In some contexts it can overlap with ideas like account or reason, but explanation is the safest choice here.

In your sentence, her explanation is clearly the best match.