Learn Hardcore Korean: barami ganghaeseo ppallaejipgereul an sseumyeon osi geonjodaeeseo tteoreojyeo. - The wind is strong, so if you don’t use clothespins, the clothes fall off the drying rack.

Breakdown of barami ganghaeseo ppallaejipgereul an sseumyeon osi geonjodaeeseo tteoreojyeo.

Why are there two 이/가 markers in this sentence: 바람이 and 옷이?

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

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.

What does 강해서 mean, and how is it formed?

강해서 comes from the adjective 강하다 = to be strong.

It is formed like this:

Here -해서 means because or since.

So 바람이 강해서 means because the wind is strong.

Is 강하다 natural with 바람, or is 세다 more common?

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

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

바람이 세서 빨래집게를 안 쓰면 옷이 건조대에서 떨어져.