倍加

1. Origins, structure, and basic meaning

• Structure: 倍加, read ばいか, denotes a doubling or twofold increase and forms the verb 倍加する.
• Basic usage: 不安が倍加する depicts anxiety increasing; 勇気は倍加した reports courage after it doubled.

2. Common pitfalls and similar expressions

• General increase and completed doubling
  • The quantity increased is the subject. する presents the process, whereas した presents its completed result.