内

1. Origins, structure, and basic meaning

• Structure: Written 内 and read うち, it marks either the inside of a boundary or a subset within a larger group.
• Basic usage: It describes a garden inside a gate and selects ten students from among all participants.

2. Common pitfalls and similar expressions

• Spatial inside versus subset
  • The surrounding construction shows whether it refers to an enclosed place or to part of a group.