oppose · reverse

1. Origins, structure, and basic meaning

• Structure: 反 conveys going against something or being opposite; it is read はん in the words here.
• Basic usage: 反対 means opposition or the opposite side, while 違反 means breaking a rule or similar requirement.

2. Common pitfalls and similar expressions

• Opinion and location
  • 計画に反対する expresses disagreement with a plan.
  • 駅の反対側 describes a location on the opposite side relative to the station.