代える

1. Origins, structure, and basic meaning

• Structure: 代える(かえる) is a transitive verb for substituting one person or thing for another.
• Basic usage: Its core pattern is XをYに代える, and 社員に代えて means acting in place of an employee.

2. Common pitfalls and similar expressions

• Two substitution patterns
  • In XをYに代える, X is the original and Y the substitute; in Xに代えて, X is the person or thing being replaced.
• Difference from 代わる
  • 代える transitively replaces something, whereas 代わる describes a subject taking another's place.