stopper

1. Origins, structure, and basic meaning

• Structure: 栓 has 10 strokes and refers to a stopper that closes a hole or a container's opening.
• Basic usage: 栓, a stopper, is read せん, while 栓抜き, a bottle opener, is read せんぬき.

2. Common pitfalls and similar expressions

• What is removed and the tool used
  • In 瓶の栓を抜く, the bottle stopper is the object being removed, so it takes を.
  • In 栓抜きで瓶のふたを開けた, the bottle opener is the tool used to open the cap, so it takes で.