Walaupun mereka sempat bertengkar, mereka akhirnya saling memaafkan.

Walaupun means although / even though.

In most everyday contexts, walaupun, walau, meskipun, and meski are very close in meaning and are often interchangeable.

Examples:

• Walaupun mereka sempat bertengkar, ...
• Meskipun mereka sempat bertengkar, ...

Both are natural. A learner can safely treat walaupun and meskipun as near-equivalents here.

It is repeated for clarity and natural sentence structure.

The sentence has:

• a concessive clause: Walaupun mereka sempat bertengkar
• a main clause: mereka akhirnya saling memaafkan

Repeating mereka makes the subject of the main clause explicit again. This is very normal in Indonesian.

If you did not repeat it, the sentence could sound less complete or more conversational. Repeating it helps the sentence feel clear and balanced.

Here, sempat suggests that the action did happen at some point, often before another event or outcome.

So sempat bertengkar means something like:

• did end up arguing
• had argued at one point
• were involved in an argument before things changed

It often carries a nuance that the action occurred for a time before the later result: akhirnya saling memaafkan.

It does not just mean briefly in a simple time sense. The nuance is more like it happened before the later resolution.

They are related, but not the same.

• pernah = ever / once / at some time in the past
• sempat = had the chance/time to, or did happen before something else changed

Compare:

• Mereka pernah bertengkar.
  = They have argued before / They once argued.

• Mereka sempat bertengkar.
  = They did get into an argument, before things later moved on.

In this sentence, sempat fits well because the sentence contrasts the argument with the later forgiveness.

Bertengkar means to argue, to quarrel, or to have a fight verbally.

The prefix ber- often forms verbs that describe:

• an activity
• a state
• something done without a direct object
• sometimes a mutual activity

So bertengkar is an intransitive verb: you do not normally put a direct object after it.

For example:

• Mereka bertengkar. = They argued.
• Not normally: Mereka bertengkar dia.

In this sentence, bertengkar already implies that the people are in conflict with each other.

Akhirnya means finally, eventually, or in the end.

It shows that the forgiveness happened after the earlier conflict. It helps create the contrast:

• first: they argued
• later: they forgave each other

So it gives the sentence a sense of progression and resolution.

It is very natural in this position:

• mereka akhirnya saling memaafkan

You could also hear:

• akhirnya mereka saling memaafkan

Both are natural.

Saling means each other or mutually.

It is used before a verb to show that the action goes both ways.

So:

• memaafkan = to forgive someone
• saling memaafkan = to forgive each other

Other examples:

• saling membantu = help each other
• saling mengenal = know each other
• saling mencintai = love each other

This is a very common and useful Indonesian pattern.

Without saling, memaafkan usually needs an object or clearer context.

• Mereka akhirnya memaafkan dia. = They eventually forgave him/her.
• Saya memaafkan kamu. = I forgive you.

But in this sentence, the meaning is reciprocal: they forgave each other. That is why saling is used.

So:

• mereka akhirnya saling memaafkan = clear and natural
• mereka akhirnya memaafkan = incomplete or unclear on its own

Memaafkan comes from maaf, which learners often first meet as sorry / excuse me / forgiveness.

As a verb, Indonesian commonly uses the pattern meN- ... -kan to form verbs such as:

• memaafkan = to forgive

So:

• maaf = forgiveness / sorry
• memaafkan = to forgive someone

Examples:

• Saya memaafkan dia.
• Dia belum memaafkan saya.

In your sentence, saling memaafkan means the two sides both do that action to each other.

Yes. That would also be correct.

These are very close:

• mereka akhirnya saling memaafkan
• mereka akhirnya memaafkan satu sama lain

The version with saling is shorter and very common.
The version with satu sama lain is a bit fuller and can sound slightly more explicit.

Both mean they eventually forgave each other.

It is standard and helpful.

The first part, Walaupun mereka sempat bertengkar, is a dependent clause introducing contrast. The comma marks the boundary before the main clause:

• mereka akhirnya saling memaafkan

In careful writing, this punctuation is a good choice because it makes the sentence easier to read.

In very informal writing, people may sometimes omit commas, but the comma here is absolutely natural and recommended.

Yes, a little.

For example, these are natural:

• Walaupun mereka sempat bertengkar, mereka akhirnya saling memaafkan.
• Walaupun mereka sempat bertengkar, akhirnya mereka saling memaafkan.

The original sentence is very natural. Indonesian allows some flexibility, especially with words like akhirnya, but not every rearrangement sounds equally good.

The original version is a strong model to learn from because it is clear and idiomatic.

Yes. It follows a very common Indonesian pattern:

• Walaupun / Meskipun + clause, main clause

So the structure is:

• Walaupun they argued,
• they eventually forgave each other.

This is a useful pattern for expressing contrast:

• Walaupun dia lelah, dia tetap bekerja.
• Meskipun hujan, mereka datang juga.

So this sentence is a good example of how Indonesian builds although/even though sentences.