妨げる

1. Origins, structure, and basic meaning

• Structure: 妨げる(さまたげる) is a transitive verb for obstructing an activity or preventing movement from proceeding smoothly.
• Basic usage: It applies to an abstract activity in 会話を妨げる and a physical flow in 川の流れを妨げる.

2. Common pitfalls and similar expressions

• Abstract and physical obstruction
  • It can describe noise interfering with conversation or a tree blocking the flow of water.
• Object particle
  • Mark the obstructed activity or flow with を; the cause of the obstruction becomes the sentence's subject.