変

1. Origins, structure, and basic meaning

• Structure: 変 is read as へん and can mean “strange” or “suspicious”, depending on context.
• Basic usage: The examples show a strange machine noise and an unfamiliar box seeming suspicious.

2. Common pitfalls and similar expressions

• Distinguishing senses and uses
  • It is a na-adjective meaning odd or suspicious; use 変な before a noun and 変だ as a sentence predicate.