chinguga jinsireul malhaesseo.

They are particles, and they show the role of each noun in the sentence.

• 친구가 = the friend
  • subject marker
• 진실을 = the truth
  • object marker

So in 친구가 진실을 말했어, the friend is the one doing the action, and the truth is what was said.

A very literal breakdown is:

• 친구가 = friend
  • subject marker
• 진실을 = truth
  • object marker
• 말했어 = said / told

So the structure is basically:

[subject] + [object] + [verb]

Both are possible, but they feel different.

• 친구가 진실을 말했어 puts focus on the friend as the subject.
  • It can sound like The friend told the truth or It was the friend who told the truth.
• 친구는 진실을 말했어 sounds more like As for the friend, they told the truth or sets up a contrast.
  • For example: Everyone else lied, but the friend told the truth.

So 가 is often used when introducing or identifying the subject, while 는 often adds topic or contrast.

말했어 is the past tense of 말하다, which means to speak / to say / to tell depending on context.

Here:

• 말하다 = to say / to speak
• 말했어 = said / told

In this sentence, 진실을 말했어 means told the truth.

This form is:

• past tense
• casual/informal speech
• polite enough for friends or people close to you, but not for formal situations

The polite version would be:

• 친구가 진실을 말했어요.

This is a normal past-tense change in Korean.

• dictionary form: 말하다
• stem: 말하-
• past marker: -았/었-
• casual ending: -어

So it becomes:

• 말하 + 였어
• which contracts to 말했어

This same pattern happens with many 하다 verbs:

• 공부하다 → 공부했어
• 일하다 → 일했어
• 이야기하다 → 이야기했어

Yes. 진실을 말하다 means to tell the truth or to speak the truth.

It is a natural expression, though in everyday conversation Koreans also very often say:

• 진실을 말했어 = told the truth
• 사실을 말했어 = told the truth / told the facts
• 솔직하게 말했어 = spoke honestly

There can be slight nuance differences:

• 진실 = truth in a deeper or moral sense
• 사실 = fact, something factual
• 솔직하게 = honestly, frankly

But in many situations, learners can understand 진실을 말했어 simply as told the truth.

In natural English, told the truth is usually the best translation.

Even though 말하다 often means to say, Korean does not always match English word-for-word. So:

• 진실을 말했어 → told the truth

not usually:

• said the truth

because said the truth sounds unnatural in English.

This is a good example of why you should translate by meaning, not by matching one Korean word to one English word.

Yes, very often.

If the context is clear, Korean can drop nouns that English usually keeps.

For example:

• 진실을 말했어. = (Someone) told the truth.
• 친구가 말했어. = The friend said it / spoke.
• 말했어. = (Someone) said it / told (me/us).

Korean relies heavily on context, so full sentences like 친구가 진실을 말했어 are often used when the speaker wants to be clear, specific, or emphasize who did what.

Korean word order is more flexible than English because particles show each word’s role.

The basic order is:

• 친구가 진실을 말했어

But you may also see:

• 진실을 친구가 말했어

This is still grammatical because:

• 가 marks the subject
• 을 marks the object

However, changing the order changes the emphasis.
For example:

• 친구가 진실을 말했어 = neutral/basic order
• 진실을 친구가 말했어 = stronger focus on the truth

Even though order can move around, the verb usually stays near the end in Korean.

A natural pronunciation is close to:

• 친구가 → chin-gu-ga
• 진실을 → sounds closer to jin-shi-reul
• 말했어 → sounds close to mal-hae-sseo

Together, it sounds roughly like:

• chin-gu-ga jin-shi-reul mal-hae-sseo

A couple of useful pronunciation notes:

• In 진실을, the 을 attaches smoothly to the previous syllable, so it sounds like 실을
• 말했어 is pronounced with a tense ss sound in 했어

So the whole sentence flows smoothly rather than sounding like three completely separate words.

말했어 is in the casual informal style, often called 해체.

You can use it with:

• close friends
• people younger than you
• family members
• casual conversation

You would usually not use it with:

• your boss
• a teacher
• someone you just met
• formal situations

More polite versions are:

• 친구가 진실을 말했어요. = polite everyday speech
• 친구가 진실을 말했습니다. = formal speech

So the sentence you have is natural if the speaker is talking casually.