i gugeun masi jinhaeseo babirang jal eoullyeoyo.

은 marks 이 국 as the topic: as for this soup...

So the sentence is setting up the soup as the thing being talked about:

• 이 국은 = as for this soup

If you said 이 국이, it would sound more like the soup itself is being specifically identified as the subject in contrast to something else. Both can be possible in different contexts, but 은 is very natural here because the speaker is making a comment about the soup.

국 means soup in Korean, especially a Korean-style soup served with rice.

It is a very common everyday word in meals. Learners often compare it with:

• 국 = soup
• 탕 = soup, often a little heartier or more substantial
• 찌개 = stew, usually thicker/stronger than 국

In this sentence, 국 is simply soup.

진해서 comes from the adjective 진하다, which means to be thick, deep, rich, or strong in flavor, color, concentration, etc.

Breakdown:

• 진하다 = to be rich/strong/deep
• stem: 진하-
• -아서/어서 = because / so / and
• 진하- + 여서 becomes 진해서

This is a common contraction with 하다 adjectives:

• 진하여서 → 진해서

So 맛이 진해서 means:

• because the flavor is rich/strong
• or more naturally, since it has a rich flavor

Literally:

• 맛 = taste, flavor
• 이 = subject marker
• 진하다 = be rich/strong/deep

So 맛이 진하다 literally means:

• the taste is strong/deep

In natural English for food, it often means:

• the flavor is rich
• the flavor is strong
• it has a deep flavor

It usually does not mean spicy. For spicy, Korean would usually use 맵다.

Because inside the larger sentence, 맛 is the subject of the descriptive clause.

The whole sentence has this structure:

• 이 국은 = as for this soup
• 맛이 진해서 = because its flavor is rich
• 밥이랑 잘 어울려요 = it goes well with rice

So:

• 국은 = main topic of the sentence
• 맛이 = subject inside the reason clause

This kind of topic + internal subject structure is very common in Korean.

Here, -아서/어서 gives a reason or connection:

• because
• so
• and therefore

So 맛이 진해서 밥이랑 잘 어울려요 means:

• Because the flavor is rich, it goes well with rice
• or more naturally, It has a rich flavor, so it goes well with rice

This ending can also simply connect actions or descriptions, but in this sentence the reason meaning is the most natural one.

이랑 means with.

So:

• 밥이랑 = with rice

Here it shows what the soup pairs with:

• 밥이랑 잘 어울려요 = it goes well with rice

이랑 is conversational and very common in speech. Other similar forms are:

• 밥하고
• 밥과
• 밥와 is incorrect; it should be 밥과 or 밥이랑/밥하고

A quick comparison:

• 이랑/랑 = casual spoken with
• 하고 = also common spoken with
• 와/과 = more neutral or formal written/spoken with

Because 밥 ends in a consonant, you use 이랑, not 랑.

Because 어울리다 does not normally take 을/를 for the thing it matches with.

With 어울리다, Korean usually uses particles meaning with:

• N이랑 어울리다
• N하고 어울리다
• N와/과 어울리다

So:

• 밥이랑 잘 어울려요 = It goes well with rice

Using 밥을 would be unnatural here.

어울리다 means to suit, to match, or to go well with.

With food, it often means:

• to pair well with
• to go well with

So 잘 어울려요 means:

• goes well
• pairs well
• matches well

Examples:

• 김치는 라면이랑 잘 어울려요.
  Kimchi goes well with ramen.
• 그 색은 너한테 잘 어울려요.
  That color suits you well.

So the same verb is used for food, clothes, colors, people, and more.

잘 means well.

So:

• 어울려요 = it matches / it goes together
• 잘 어울려요 = it matches well / it goes well together

You could say just 어울려요, but 잘 어울려요 is much more natural when praising a good combination.

Yes. 어울려요 is in the polite informal style, which is very common in everyday conversation.

Original:

• 이 국은 맛이 진해서 밥이랑 잘 어울려요.

Casual:

• 이 국은 맛이 진해서 밥이랑 잘 어울려.

Formal:

• 이 국은 맛이 진해서 밥이랑 잘 어울립니다.

All three mean the same thing, but the level of politeness changes.

In natural English, both ideas are basically the same: they pair well together.

But grammatically, Korean is framing the sentence around the soup:

• As for this soup, because its flavor is rich, it goes well with rice.

So the soup is the main topic, and rice is the thing it pairs with.

That said, Korean often leaves some things flexible in meaning when the relationship is obvious, so the main point is simply:

• this soup and rice are a good combination