臭い

1. Origins, structure, and basic meaning

• Structure: 臭い(くさい) means smelling bad or, figuratively, seeming suspicious.
• Basic usage: For a literal odor it appears in 靴が臭い; for a suspicious account it appears in その話は臭い.

2. Common pitfalls and similar expressions

• Separate the literal and figurative senses
  • With an object or place as subject it often refers to odor; with a story or behavior it can mean suspicious.
• Difference from 匂う
  • 匂う(におう) can neutrally say that something gives off a smell, while 臭い normally indicates a bad odor or negative suspicion.