Hun hjelper meg; til gjengjeld hjelper jeg henne.

Til gjengjeld is a fixed expression meaning in return, in exchange, or as a return favor.

So the sentence means that one person helps, and the other person helps back.

It is best learned as one whole chunk: til gjengjeld.
Trying to understand it word by word is usually less helpful than simply memorizing the expression.

Because Norwegian pronouns change form depending on their role in the sentence.

• hun = she → subject form
• henne = her → object form

In Hun hjelper meg, hun is the person doing the helping, so it is the subject.

In hjelper jeg henne, henne is the person receiving the help, so it is the object.

This is similar to English:

• she helps me
• I help her

For the same reason:

• jeg = I → subject form
• meg = me → object form

In Hun hjelper meg, meg is the object, because it is the person being helped.

So:

• jeg hjelper henne = I help her
• hun hjelper meg = she helps me

This is because Norwegian normally follows the V2 rule in main clauses: the finite verb usually comes in the second position.

In the second clause, til gjengjeld comes first. That means the verb must come next:

• Til gjengjeld hjelper jeg henne.

Not:

• Til gjengjeld jeg hjelper henne. ❌

This is a very common Norwegian pattern. Compare:

• I dag kommer han.
• Nå går jeg.
• Til gjengjeld hjelper jeg henne.

When something other than the subject comes first, the verb usually moves before the subject.

Because Norwegian verbs do not change form for different persons in the present tense.

So you say:

• jeg hjelper
• du hjelper
• hun hjelper
• vi hjelper

This is easier than English, which has forms like I help but she helps.

In Norwegian, the present tense form stays the same.

Hjelper is the present tense of å hjelpe.

• å hjelpe = to help
• hjelper = help / helps / am helping / is helping, depending on context

In this sentence, it describes a general present situation: one person helps, and the other helps in return.

Yes. Til gjengjeld is normally treated as a set phrase.

That means learners should usually memorize it as one unit rather than trying to build it freely from separate words.

You will often see it used to mean things like:

• in return
• on the other hand, as compensation
• in exchange

So this sentence is very natural Norwegian.

The semicolon links two closely related main clauses:

• Hun hjelper meg
• til gjengjeld hjelper jeg henne

It shows a stronger connection than a full stop, but a clearer division than a comma.

You could also write:

• Hun hjelper meg. Til gjengjeld hjelper jeg henne.

That is also correct.

A semicolon is a style choice here. It is not changing the basic grammar.

Usually, it is better not to do that here.

Since these are two full main clauses, a comma alone would generally not be the best choice in standard writing:

• Hun hjelper meg, til gjengjeld hjelper jeg henne.

Some people may write it that way, but a semicolon or full stop is safer and more standard.

Yes, that is possible.

• Til gjengjeld hjelper jeg henne.
• Jeg hjelper henne til gjengjeld.

Both are grammatical.

The version with til gjengjeld first gives it more emphasis. It highlights the idea of in return more strongly.

So the original sentence sounds natural and slightly more focused on the reciprocal relationship.

Yes. It describes a mutual exchange:

• She helps me
• I help her in return

Norwegian does not need a special verb form for this. It simply states both actions clearly.

That is why the pronouns are important:

• hun → the first helper
• meg → the first receiver
• jeg → the second helper
• henne → the second receiver

The sentence neatly shows that the help goes both ways.