bend · hook

1. Origins, structure, and basic meaning

• Structure: 勾 has meanings connected with bending or a hook; its on-reading is こう.
• Basic usage: It forms distinct words such as 勾配, meaning slope or gradient, and 勾留, meaning detention.

2. Common pitfalls and similar expressions

• Reading a slope term
  • 勾配 is read こうばい. 勾配が急 means that a slope is steep and can describe a hillside or roof.
• A word in legal contexts
  • 勾留 is read こうりゅう and is used for detaining a person. Understand the complete word rather than translating the character literally as bending.