別人

1. Origins, structure, and basic meaning

• Structure: 別人(べつじん) means a different person from the one previously mentioned or expected.
• Basic usage: It is used both for a striking change in appearance and for a genuinely different individual.

2. Common pitfalls and similar expressions

• Appearance and actual identity
  • 別人のように見えた means looked like a different person, describing an impression of someone's appearance.
  • 別人だと分かった means realized it was a different person, expressing a judgment about identity.