cause

1. Origins, structure, and basic meaning

• Structure: 因 is associated with causes or factors behind a result; its on-reading is いん.
• Basic usage: 原因(げんいん) means the cause of an event, while 要因(よういん) means a factor influencing a result.

2. Common pitfalls and similar expressions

• A specified cause and factors being analyzed
  • If the 音が出なかった原因 was a disconnected wire, the reason for the lack of sound has been specifically identified. Analyzing 成功の要因 in three categories examines elements contributing to success.
  • This usage difference does not make causes always singular or factors always plural. In 睡眠不足も集中力を下げる要因になる, lack of sleep is itself a factor that reduces concentration.