永遠

1. Origins, structure, and basic meaning

• Structure: 永遠 is read as えいえん and is a noun for eternity or a state continuing without an end in time.
• Basic usage: Endless continuation appears in 永遠に続く, while eternal life appears in 永遠の命.

2. Common pitfalls and similar expressions

• Uses with に and の
  • Use 永遠に to describe an action continuing forever and 永遠の to modify a noun with the meaning eternal.
• Difference from 永久
  • The meanings are close, but 永遠 readily carries an abstract or emotional sense of endless time, while 永久 often describes permanent continuation.