geu gwanggoreul mandeun sarami jakgarago deureosseo.

만든 is the past-tense modifier form of 만들다 (to make). In Korean, verbs can directly modify nouns, kind of like a relative clause in English.

So:

• 만든 사람 = the person who made (it)
• literally: made person

In full structure:

• 그 광고를 만든 사람 = the person who made that advertisement

This is very common in Korean:

• 어제 만난 사람 = the person I met yesterday
• 제가 읽은 책 = the book I read

The 이/가 particle marks the subject of the clause. Here, 사람이 is the subject of the larger statement:

• 그 광고를 만든 사람 = the person who made that ad
• 그 광고를 만든 사람이 작가라고 들었어 = I heard that the person who made that ad is a writer

So 사람이 is the person being identified as 작가.

A helpful way to see it:

• X이/가 Y라고 들었어 = I heard that X is Y

Here:

• X = 그 광고를 만든 사람
• Y = 작가

작가라고 is made from:

• 작가 = writer / author / artist (depending on context)
• -라고 = a quotation marker used after nouns

So 작가라고 들었어 literally means:

• I heard (someone say) that (they) are a writer

In Korean, when reporting speech or information:

• after a noun, use -라고 하다 / 들었다
• after a verb/adjective clause, different forms are used, such as -다고

Examples:

• 학생이라고 했어 = They said he is a student
• 의사라고 들었어 = I heard she is a doctor

So here, 작가라고 들었어 means I heard that they’re a writer/author.

These are different speech levels:

• 들었어 = casual / informal
• 들었어요 = polite
• 들었다 = plain written style / narrative style / sometimes blunt spoken style

So the sentence as given is casual, probably said to a friend.

Comparison:

• 그 광고를 만든 사람이 작가라고 들었어.
  Casual: I heard the person who made that ad is a writer.

• 그 광고를 만든 사람이 작가라고 들었어요.
  Polite: same meaning, more respectful

If you are learning Korean for conversation, this difference is very important.

Yes, but in Korean it often means I heard that..., meaning I was told or I learned from someone else.

So it does not always mean physically hearing a sound. It often introduces reported information.

Examples:

• 그 사람 미국 갔다고 들었어. = I heard that person went to the U.S.
• 내일 비 온다고 들었어. = I heard it’s going to rain tomorrow.

So in this sentence, 들었어 shows that the speaker is passing along information they heard from another source.

No, nothing is missing. The sentence is complete as it is.

Korean often avoids repeating information that is already clear. The structure is:

• 그 광고를 만든 사람 = the person who made that ad
• 그 사람이 작가라고 들었어 = I heard that person is a writer

These combine naturally into:

• 그 광고를 만든 사람이 작가라고 들었어

So even though English might feel like it needs a clearer separation, Korean handles this smoothly in one sentence.

를 is the object marker. It marks 광고 (advertisement/ad) as the thing being made.

So:

• 광고를 만들다 = to make an advertisement

In the phrase:

• 그 광고를 만든 사람 it means:
• the person who made that advertisement

The structure is:

• 그 광고를 = that advertisement + object marker
• 만든 = made
• 사람 = person

그 usually means that in Korean, not exactly the.

So:

• 그 광고 = that advertisement

In real translation, depending on context, English might say:

• that ad
• the ad

Korean does not have articles like a/the, so 그 is often used when referring to something already known in the conversation.

Compare:

• 광고 = an ad / ads / the ad (depends on context)
• 그 광고 = that ad / the ad we’re talking about

Yes. 작가 often means writer or author, but depending on context it can also mean a creative artist, especially someone known for producing creative works.

Common uses include:

• novelist
• screenwriter
• author
• literary writer
• sometimes artist/creator in a broader sense

So if the sentence context is about advertising, media, or art, 작가 could have a slightly broader nuance than just writer. The exact English translation depends on context.

A good breakdown is:

• 그 광고를 만든 사람 = the person who made that ad
• 이/가 = subject marker
• 작가라고 = that (they are) a writer
• 들었어 = I heard

So the full structure is:

• [그 광고를 만든 사람]이 [작가]라고 들었어.
• I heard that [the person who made that ad] is [a writer].

This is a very common Korean pattern:

• [noun-modifying clause + noun]이/가 [noun]라고 들었어
• I heard that [the noun described by the clause] is [something]

Yes. The original sentence is already natural in casual speech, but here are some variations.

Casual

• 그 광고를 만든 사람이 작가라고 들었어.

Polite

• 그 광고를 만든 사람이 작가라고 들었어요.

A little more explicit

• 그 광고를 만든 사람이 작가라는 얘기를 들었어.
  = I heard that the person who made that ad is a writer.

Formal / written

• 그 광고를 만든 사람이 작가라고 들었습니다.

All of these are natural, but the original is a very standard conversational sentence.