양말을

양말을

"양말을" means "socks" in the accusative form (as the object of a sentence).

양말을 is the object of the verb 신는다 (wear), indicating what is being worn.

나는 양말을 신는다.

I wear socks.

양말을 is the direct object of the verb 넣는다 (put), specifying what is being put into the shoes.

신발에 양말을 넣는다.

I put socks into the shoes.

양말을 is the object of the verb 넣어야 한다 (need to put), defining what needs to be put into the washing machine.

양말을 세탁기에 넣어야 한다.

You need to put the socks into the washing machine.