←
English hard (semantic loan)
←
Proto-Vietic *kəŋʔ (inherited)
←
Vietnamese nứng (mention)
←
Vietnamese kình (mention)
←
Vietnamese cường (mention)
←
Vietnamese cưỡng (mention)
←
Vietnamese cương (mention)
←
Vietnamese kiên (mention)
→
Vietnamese nứng (mention)
→
Vietnamese ổ cứng (compound)