古今

1. Origins, structure, and basic meaning

• Structure: 古今 is read ここん.
• Basic usage: It refers to past and present together or to all ages.

2. Common pitfalls and similar expressions

• Works from past and present
  • 古今の名作: masterpieces from both past and present.
• Throughout the ages
  • 古今を通じて: across all ages from the past to the present.