mullon, gati jeongsange gaja.

물론 means of course.

In this sentence, it shows an enthusiastic or confident agreement with something said earlier. For example, if someone asked 같이 정상에 갈래? (Do you want to go to the top together?), the reply 물론, 같이 정상에 가자. means something like Of course, let’s go to the top together.

A few useful notes:

• 물론 is often used by itself as a full reply: Of course.
• It can sound a little stronger or more definite than just a casual yes.
• In everyday speech, Koreans also often use things like 그럼, 당연하지, or 응 depending on tone and situation.

같이 means together.

So 같이 정상에 가자 means let’s go to the top together.

It does not literally function exactly like the English preposition with, although in translation it can feel similar. Korean often uses 같이 where English would naturally say with someone or together.

For example:

• 같이 가자 = Let’s go together
• 친구랑 같이 가자 = Let’s go together with a friend

Also, 같이 is very common in speech. A similar word is 함께, which also means together, but 함께 can sound a bit more formal or literary.

정상 usually means the top, the summit, or the peak, especially of a mountain.

So in this sentence, 정상에 가자 most naturally means let’s go to the summit or let’s go to the top.

Be careful, because 정상 can also mean normal in other contexts. For example:

• 정상입니다 = It is normal
• 정상에 도착했다 = (We) arrived at the summit

So the meaning depends on context. In 정상에 가자, because it is followed by 에 가다 (go to), it clearly means summit/top.

The particle 에 marks the destination of movement here.

Since 가다 means to go, Korean usually marks the place you go to with 에:

• 학교에 가다 = to go to school
• 집에 가다 = to go home
• 정상에 가다 = to go to the summit

So 정상에 가자 literally means let’s go to the summit.

This is one of the most common uses of 에: marking a location or destination.

가자 is the let’s go form of 가다 (to go).

It is not exactly a command like Go! Instead, it is a suggestion or proposal that includes the speaker:

• 가자 = let’s go
• 먹자 = let’s eat
• 보자 = let’s see

This form is often called the propositive form.

So 같이 정상에 가자 means let’s go to the top together, not go to the top together.

No, 가자 is informal and casual.

It is fine when speaking to:

• close friends
• younger people
• family members
• someone you are on casual terms with

It would not normally be appropriate in a formal situation or to someone you should speak politely to.

More polite versions would be:

• 같이 정상에 가요. = Let’s go to the top together.
• 같이 정상에 갑시다. = Let’s go to the top together.
  This is more formal or deliberate.

So the original sentence has a friendly, casual tone.

Korean very often omits the subject when it is clear from context.

In English, we usually need to say we in Let’s go to the top together. In Korean, the meaning is already built into 가자, since that form naturally means let us go / let’s go.

So there is no need to say 우리 unless the speaker wants emphasis or contrast.

For example:

• 같이 정상에 가자. = Let’s go to the top together.
• 우리 같이 정상에 가자. = Let’s go to the top together.
  This can sound a little more explicit or warm.

Omitting the subject is very normal in Korean.

Yes. 함께 정상에 가자 is also correct and means basically the same thing: let’s go to the top together.

The difference is mostly in tone:

• 같이 = very common, natural, conversational
• 함께 = a bit more formal, written, or polished

In everyday speech between friends, 같이 is usually the more natural choice.

The comma is just separating the introductory word 물론 from the rest of the sentence.

It helps show the pause you might make in speech:

• 물론, 같이 정상에 가자.
• Of course, let’s go to the top together.

In Korean writing, punctuation is somewhat flexible, especially in casual contexts. The comma is helpful, but you may also see the sentence written without it:

• 물론 같이 정상에 가자.

Both are understandable.

It can sound perfectly natural in the right context, especially if two people are hiking or talking about reaching a summit.

However, depending on the situation, a native speaker might choose slightly different wording. For example:

• 물론, 같이 올라가자. = Of course, let’s go up together.
• 물론이지. 같이 가자. = Of course. Let’s go together.
• 그래, 같이 정상까지 가자. = Yeah, let’s go all the way to the summit together.

So the original sentence is grammatical and clear, but real-life speech may vary depending on tone, context, and how specifically the speaker wants to mention the summit.