証

1. Origins, structure, and basic meaning

• Structure: The single kanji 証, given the kun reading あかし, is a noun for proof or a token supporting a fact.
• Basic usage: 証だ identifies something as proof, while 証として marks it as serving in the role of proof.

2. Common pitfalls and similar expressions

• Predication and role marking
  • Read あかし, it denotes evidence or a token rather than the act of proving.