国内

1. Origins, structure, and basic meaning

• Structure: 国内 is read as こくない; 国 (country) and 内 (inside) denote territory within a country or something domestic.
• Basic usage: Use 国内を旅行する for the area traveled and 国内の工場 to modify a factory as domestic.

2. Common pitfalls and similar expressions

• Range and modification
  • 国内を marks the spatial range of travel, while 国内の specifies where the following factory is located.
• Reference country comes from context
  • The word does not inherently mean Japan in every use; it means within the country established by the context.