barami ganghaeseo ppallaejipgereul an sseumyeon osi geonjodaeeseo tteoreojyeo.

Because the sentence contains more than one clause, and each clause can have its own subject.

• 바람이 강해서 = because the wind is strong
  • subject: 바람이
• 옷이 건조대에서 떨어져 = the clothes fall off the drying rack
  • subject: 옷이

So this is not one clause with two subjects. It is a longer sentence made of connected parts, and each part has its own grammar.

강해서 comes from the adjective 강하다 = to be strong.

It is formed like this:

• 강하다
• stem: 강하-
• connective ending: -아서/어서/해서
• 강하 + 여서 → 강해서

Here -해서 means because or since.

So 바람이 강해서 means because the wind is strong.

Both are understandable, but 바람이 세다 is more common in everyday Korean for the wind is strong.

• 바람이 세서 sounds very natural and common.
• 바람이 강해서 is also possible, but slightly less everyday.

So the sentence is understandable as written, but many native speakers might more naturally say:

바람이 세서 빨래집게를 안 쓰면 옷이 건조대에서 떨어져.

빨래집게 means clothespin or laundry clip.

It is a compound noun:

• 빨래 = laundry
• 집게 = clip, tongs, pinching tool

So 빨래집게 is literally something like laundry clip.

안 쓰면 means if you don’t use (it/them).

It breaks down like this:

• 쓰다 = to use
• 안 = not
• 쓰면 = if/when (someone) uses
• 안 쓰면 = if/when (someone) does not use

So in this sentence, 빨래집게를 안 쓰면 means if you don’t use clothespins.

Both mean if you don’t use.

• 안 쓰면 = shorter, more conversational
• 쓰지 않으면 = more formal, more written, or slightly more emphatic

In everyday speech, 안 쓰면 is very common and natural.

So:

• 빨래집게를 안 쓰면 = casual/natural
• 빨래집게를 쓰지 않으면 = more formal

Because they do different jobs.

• -해서 gives a reason/background: because the wind is strong
• -면 gives a condition: if you don’t use clothespins
• the final clause gives the result: the clothes fall off the drying rack

So the logic is:

Because it’s windy, if you don’t use clothespins, the clothes fall off the drying rack.

Korean often stacks clauses like this, with the result coming at the end.

Because 떨어지다 is an intransitive verb. That means the thing that falls is the subject, not the object.

So:

• 옷이 떨어져 = the clothes fall
• not 옷을 떨어져

If you wanted a transitive verb, you would use 떨어뜨리다 = to drop something.

For example:

• 바람이 옷을 떨어뜨렸어 = the wind dropped the clothes
• 옷이 떨어졌어 = the clothes fell

Here 에서 marks the place something falls from.

So:

• 건조대에서 떨어져 = fall from / off the drying rack

With 떨어지다, Korean often uses 에서 for the source location.

By contrast, 에 often marks a destination or place where something ends up.

So:

• 건조대에서 떨어지다 = fall off the drying rack
• 바닥에 떨어지다 = fall onto the floor

That is why the sentence has both ideas available: something falls from one place and often onto another place.

떨어져 is the casual present form of 떨어지다.

The verb changes like this:

• dictionary form: 떨어지다
• casual polite: 떨어져요
• casual non-polite: 떨어져
• plain style: 떨어진다

So the sentence is in a casual, non-polite style.

It can mean a general result.

In Korean, the present form is often used for:

• general truths
• habits
• predictable results
• future results in condition sentences

So here 옷이 건조대에서 떨어져 does not have to mean the clothes are falling right now. It can mean:

• the clothes fall off
• the clothes will fall off
• the clothes tend to fall off

depending on context.

Yes, but the nuance changes.

• 이/가 marks the subject more neutrally or with focus
• 은/는 marks the topic and often adds contrast or background nuance

So:

• 바람이 강해서 = the wind is strong
• 바람은 강해서 = as for the wind, it is strong / the wind, at least, is strong

And:

• 옷이 떨어져 = the clothes fall
• 옷은 떨어져 = as for the clothes, they fall / the clothes end up falling

The original sentence with 이/가 sounds straightforward and natural.

Yes. In casual speech, the object marker 를 is often omitted if the meaning is still clear.

So both of these are natural:

• 빨래집게를 안 쓰면
• 빨래집게 안 쓰면

Keeping 를 is a little clearer and slightly more complete, but dropping it is very common in conversation.