i chimaneun sae sinbarirang jal eoullyeoyo.

이 means this. It comes before a noun, so 이 치마 means this skirt.

It is part of the set:

• 이 = this
• 그 = that
• 저 = that over there

So 이 치마는 starts with as for this skirt...

-는 is the topic marker. It marks 치마 as the thing the sentence is talking about.

So 이 치마는 새 신발이랑 잘 어울려요 has the feeling of: As for this skirt, it goes well with the new shoes.

It is not exactly the same as the subject marker -이/가. -는 often gives a topic or slight contrast nuance.

새 is a very common word meaning new when it comes directly before a noun, especially for everyday concrete things like clothes, shoes, bags, phones, and so on.

So 새 신발 is the natural way to say new shoes here.

새로운 also means new, but it often sounds more like new in a fresh/novel sense, and it is more common with things like:

• 새로운 아이디어 = a new idea
• 새로운 방법 = a new method

Also, here 새 does not mean bird. That is a different word that just happens to sound the same.

In Korean, nouns often do not have to be marked clearly as singular or plural the way they do in English.

So 신발 can mean:

• shoe
• shoes
• footwear

In this sentence, English naturally uses shoes, but Korean leaves that to context. If you really wanted to emphasize plural, you could say 신발들, but that is usually unnecessary.

이랑 means with here, and sometimes it can also mean and depending on the sentence.

In this sentence, 새 신발이랑 잘 어울려요 means goes well with the new shoes.

이랑 is a casual, spoken-style particle. Other similar forms are:

• 하고
• 와/과

So these are all possible:

• 새 신발이랑 잘 어울려요
• 새 신발하고 잘 어울려요
• 새 신발과 잘 어울려요

The last one sounds more formal/written.

잘 usually means well, but not always in the sense of doing something skillfully.

With 어울리다, 잘 means something like:

• well
• nicely
• in a matching way

So 잘 어울려요 means:

• looks good together
• matches well
• goes well

The dictionary form is 어울리다, which means to suit, to match, or to go well with.

The polite present form is 어울려요.

This happens because verbs ending in -리다 often contract when -어요 is added:

• 어울리다 → 어울려요
• 기다리다 → 기다려요

So 어울려요 is just the normal polite present tense form.

Because 어울리다 usually does not work like a direct-object verb in English.

In English, we say This skirt matches the shoes, where the shoes looks like a direct object. But in Korean, the pattern is more like:

• A는 B랑 어울리다 = A goes well with B
• A는 B에 어울리다 = A suits B / is suitable for B

So 새 신발이랑 is natural because the idea is with the new shoes, not the new shoes as a direct object.

Yes, you can, and it is grammatically fine.

The difference is mainly nuance:

• 치마는 = as for the skirt... / topic / possible contrast
• 치마가 = stronger focus on the skirt as the subject

So:

• 이 치마는 새 신발이랑 잘 어울려요 = As for this skirt, it goes well with the new shoes.
• 이 치마가 새 신발이랑 잘 어울려요 = This skirt is the one that goes well with the new shoes.

Yes. 어울려요 is the standard polite everyday form.

You might hear:

• 어울려 = casual/plain, used with close friends
• 어울려요 = polite everyday speech
• 어울립니다 = more formal

So the sentence as written is natural and polite for normal conversation.

No. 어울리다 is used very widely for things that suit or match each other.

For example:

• 이 색은 너한테 잘 어울려요. = This color looks good on you.
• 그 가구는 이 방이랑 잘 어울려요. = That furniture goes well with this room.
• 그 일은 저한테 안 어울려요. = That job doesn’t suit me.

So in this sentence it is about clothes, but the verb itself is much broader.