banpalman ipgo nagamyeon chuul geos gataseo mokdorireul gabange neoheosseo.

반팔 means short sleeves or a short-sleeved top/shirt, and 만 means only / just.

So 반팔만 입고 means:

• wearing only a short-sleeved shirt
• or more literally, wearing just short sleeves

The 만 adds the idea that nothing warmer is being worn, which is why the speaker worries it might be cold.

In Korean, 만 is a particle that attaches directly to the noun or phrase it limits.

So:

• 반팔만 = only a short-sleeved shirt
• 물만 = only water
• 오늘만 = only today

Here, 반팔만 입고 means if I go out wearing only a short-sleeved shirt.
The focus is on the clothing being insufficient for the weather.

입다 means to wear.
The form 입고 is the -고 connective form, which links actions or states.

In this sentence, 입고 나가면 literally means:

• wearing (it) and going out
• more naturally, if I go out wearing...

So 입고 is not the final action. It sets up the condition for 나가면.

A very natural English translation is:

• if I go out in only a short-sleeved shirt

나가다 means to go out.
-면 means if / when.

So 나가면 means:

• if (someone) goes out
• if I go outside
• sometimes when I go out, depending on context

In this sentence, it gives the condition:

• If I go out wearing only a short-sleeved shirt, it seems like it’ll be cold...

Because Korean often omits the subject, I is understood from context.

This is an important nuance.

• 추워서 = because it’s cold
• 추울 것 같아서 = because I think it’ll be cold / because it seems like it might be cold

The speaker is not saying they are already definitely cold.
They are making a prediction or judgment about the weather.

So:

• 추워서 목도리를 넣었어
  = I put a scarf in my bag because it was cold

• 추울 것 같아서 목도리를 넣었어
  = I put a scarf in my bag because I thought it would be cold

The sentence you gave is about expectation, not confirmed fact.

-(으)ㄹ 것 같다 is a very common pattern meaning:

• it seems like...
• I think...
• it looks like...
• it will probably...

Here:

• 춥다 = to be cold
• 추울 = future/adnominal form of 춥다
• 것 같다 = it seems / I think

So 추울 것 같아 means:

• I think it’ll be cold
• It seems like it’ll be cold

Then -서 is added:

• 추울 것 같아서 = because I thought it would be cold

-아서/-어서 often expresses reason or cause, similar to because.

So:

• 추울 것 같아서 = because it seemed like it would be cold
• 배가 고파서 먹었어 = I ate because I was hungry
• 비가 와서 안 갔어 = I didn’t go because it rained

In your sentence, it explains why the speaker put the scarf in the bag.

Structure:

• 반팔만 입고 나가면 = if I go out wearing only short sleeves
• 추울 것 같아서 = because I think it’ll be cold
• 목도리를 가방에 넣었어 = I put a scarf in my bag

This is a basic but very useful pattern:

• 목도리를: object marker -를
• 가방에: location/destination marker 에
• 넣었어: put in

So the structure is:

• X를 Y에 넣다 = put X into Y

Here:

• 목도리를 = the scarf
• 가방에 = into the bag
• 넣었어 = put

So:

• 목도리를 가방에 넣었어 = I put a scarf in my bag

This does not mean the speaker wore the scarf. It means they packed it.

넣었어 focuses on the physical action of putting the scarf into the bag.

• 넣었어 = put in
• 가져갔어 = took/brought along

So the sentence specifically describes how the speaker prepared:

• they put the scarf in the bag

If you said 목도리를 가져갔어, it would mean:

• I took/brought a scarf with me

That is also natural, but it emphasizes carrying it along rather than the act of placing it in the bag.

Yes, the subject is omitted, which is very normal in Korean.

From the ending 넣었어 and the overall context, the implied subject is most naturally:

• I

So the full understood meaning is something like:

• I thought it would be cold if I went out wearing only a short-sleeved shirt, so I put a scarf in my bag.

Korean often leaves out I, you, or he/she when they are obvious from context.

넣었어 is in the informal casual style.

Base verb:

• 넣다 = to put in

Past casual:

• 넣었어 = put in / I put in

This style is commonly used:

• with friends
• with people younger than you
• in casual conversation
• in diaries or inner thoughts

A more polite version would be:

• 반팔만 입고 나가면 추울 것 같아서 목도리를 가방에 넣었어요.

Same meaning, just more polite.

In everyday Korean, 반팔 often stands for a short-sleeved shirt/top, not just the sleeves themselves.

So although the literal meaning is related to short sleeves, in natural use:

• 반팔 입다 = to wear a short-sleeved shirt

That is why 반팔만 입고 is very naturally understood as:

• wearing only a short-sleeved shirt

not merely having short sleeves in some abstract sense.

A very natural translation is:

• I thought it would be cold if I went out wearing only a short-sleeved shirt, so I put a scarf in my bag.

Other natural versions:

• Since it seemed like it would be cold if I went out in just a T-shirt, I put a scarf in my bag.
• I figured I’d be cold going out in only short sleeves, so I packed a scarf in my bag.

All of these capture the same basic meaning and nuance.