Learn Hardcore Indonesian: Mereka sepakat bahwa kejujuran penting dalam hubungan, jadi pasangan itu sering curhat dengan tenang. - They agree that honesty is important in a relationship, so that couple often shares their feelings calmly.

sepakat: tends to sound a bit more formal and suggests a shared, unified decision or consensus (closer to “reach an agreement” / “be in accord”).
setuju: more general “agree (with something)”, used in all kinds of contexts, from casual to formal.

In daily conversation, mereka setuju bahwa … is completely natural.
Mereka sepakat bahwa … sounds slightly more like “they came to an agreement that …” or “they were of one mind that …”.

Why is bahwa used here? Is it like “that” in English? Can I drop it?

Yes, bahwa is very similar to English “that” when it introduces a clause:

Mereka sepakat bahwa kejujuran penting dalam hubungan
→ “They agreed that honesty is important in a relationship.”

In Indonesian:

With bahwa: a bit more formal/explicit, clearly marks the start of the clause.
Without bahwa: more casual and very common in speech.

You can say:

Mereka sepakat kejujuran penting dalam hubungan …

Both are grammatical. In everyday spoken Indonesian, people often drop bahwa unless they want to sound a bit more formal or very clear.

Why is there no adalah in kejujuran penting dalam hubungan? Can I say kejujuran adalah penting?

In Indonesian, when you have:

[noun] + [adjective]

you usually do not use adalah. So:

Kejujuran penting dalam hubungan.
literally: “Honesty important in relationships.”

is perfectly normal and standard.

Using adalah before an adjective (like penting) is usually:

unnecessary
often sounds unnatural or over-formal in modern Indonesian.

So kejujuran adalah penting is technically possible in very formal or didactic language, but it sounds stiff, and most native speakers would simply say:

Kejujuran penting.
Kejujuran itu penting. (adding itu is natural, like “Honesty is important, that.”)

What does the ke- … -an pattern in kejujuran mean?

Kejujuran comes from the adjective jujur (honest).

root: jujur = honest
noun: ke-jujur-an = honesty

The ke- … -an pattern commonly turns adjectives (or sometimes verbs) into abstract nouns, often similar to English -ness, -ty, or -tion:

baik → kebaikan = goodness, kindness
adil → keadilan = justice, fairness
jujur → kejujuran = honesty

So kejujuran is “the quality/state of being honest.”

What exactly does dalam hubungan mean? Does it automatically imply a romantic relationship?

Literally, dalam hubungan means “in a relationship” or “within a relationship”.

hubungan = relationship, connection, relation (very general word)
dalam = in, inside, within

In this sentence:

kejujuran penting dalam hubungan
is naturally understood as “honesty is important in a relationship.”

Because the sentence then talks about pasangan itu (“that couple”), many readers will interpret hubungan here as a romantic relationship. But by itself, hubungan can refer to many types: work, family, friendship, etc. The context (mention of a couple) makes it sound romantic.

Why does it say pasangan itu instead of just repeating mereka in the second part?

The sentence is:

Mereka sepakat bahwa kejujuran penting dalam hubungan, jadi pasangan itu sering curhat dengan tenang.

Here’s the reference:

Mereka = “they” (some group of people)
pasangan itu = “that couple / the couple”

Common interpretation: Mereka refers to that couple. Then, instead of repeating mereka, the sentence uses the more specific noun phrase pasangan itu to remind or clarify who “they” are.

It’s a natural stylistic choice in Indonesian to alternate between a pronoun (mereka) and a descriptive noun phrase (pasangan itu) to avoid repetition and keep the reference clear.

Grammatically, you could say:

… jadi mereka sering curhat dengan tenang.

That would be fine too; it just sounds a bit less specific than pasangan itu.

What does curhat mean exactly, and is it formal?

Curhat is an informal, colloquial verb. It comes from the phrase:

curahan hati
→ literally “outpouring of the heart”

Curhat means something like:

to pour one’s heart out
to open up emotionally
to confide / to talk about one’s feelings and problems

very informal / colloquial: used a lot in speech, chats, social media.
not suitable for formal writing (official letters, academic writing, serious news articles).

In a formal sentence, you might replace curhat with something like:

berbagi perasaan (share feelings)
saling bercerita secara jujur (tell each other things honestly)
saling terbuka (be open with each other)

In sering curhat, is curhat really treated like a verb? Do I need a preposition like kepada?

Yes, in everyday Indonesian curhat behaves like a verb, even though its origin is a noun phrase.

sering curhat = (they) often confide / often pour out their feelings.

You can use it:

without an object:
Dia suka curhat. → “She likes to pour her heart out.”
with kepada (to indicate the person you confide in):
Dia curhat kepada sahabatnya. → “She confides in her best friend.”

In your sentence:

pasangan itu sering curhat dengan tenang

the object (“to each other”) is understood from context, so no kepada is needed. If you wanted to be explicit, you could say:

Pasangan itu sering saling curhat dengan tenang.
(They often confide in each other calmly.)

What does dengan tenang modify, and is there another way to say “calmly”?

Dengan tenang is an adverbial phrase:

dengan = with
tenang = calm

Together, dengan tenang = “calmly”, describing how they curhat (confide).

So:

pasangan itu sering curhat dengan tenang
= “the couple often confides (talks openly) calmly.”

Alternative ways to say “calmly”:

secara tenang – more formal / textbook.
Just tenang in informal speech:
Mereka curhat tenang saja.

But dengan tenang is a very standard and natural way to make an adverbial expression.

Why does the comma come before jadi? How is jadi used here?

The comma reflects a pause between two clauses:

Mereka sepakat bahwa kejujuran penting dalam hubungan,
(first clause)
jadi pasangan itu sering curhat dengan tenang.
(second clause)

Jadi here is a conjunction meaning:

“so,” “therefore,” “as a result.”

So the structure is:

[Reason], jadi [Result].
→ “They agreed that honesty is important in a relationship, so the couple often confides calmly.”

In conversation, jadi can also be used as a discourse marker at the beginning of a sentence, like “so…” / “well then…”, but here it clearly functions as a connector of cause and effect.

Why is it sering curhat and not curhat sering? Where do adverbs like sering usually go?

Sering means “often”, and in Indonesian the usual pattern is:

[subject] + [frequency adverb] + [verb]

So:

Pasangan itu sering curhat.
(The couple often confides.)

Other examples:

Dia selalu datang tepat waktu.
(He always comes on time.)
Kami jarang makan di luar.
(We rarely eat out.)

Putting sering after the verb (curhat sering) would sound unnatural in standard Indonesian. The normal, neutral position for sering, selalu, jarang, kadang-kadang, etc., is before the main verb.

Could we say kejujuran itu penting dalam hubungan itu? What’s the role of itu here?

Yes, you can say:

Kejujuran itu penting dalam hubungan itu.

Adding itu after nouns can:

Make the noun more specific/definite, somewhat like “the” or “that” in English.
Add a slightly emphatic or topic-marking feel, like “Honesty, that’s what is important …”

Nuance differences:

Kejujuran penting dalam hubungan.
→ General statement: “Honesty is important in relationships (in general).”
Kejujuran itu penting dalam hubungan.
→ Still quite general, but with a bit more emphasis: “Honesty, that’s important in a relationship.”
Kejujuran itu penting dalam hubungan itu.
→ Feels more specific, like you’re talking about a particular relationship that the speaker and listener know about.

In your original sentence, the more general version without itu fits well, because it sounds like a general principle they agree on.