-구-

구 • (-gu-)

1. Derives certain causative verbs. No longer productive.

   Synonyms: 이 (-i-), 히 (-hi-), 리 (-ri-), 기 (-gi-), 우 (-u-), 추 (-chu-)

   ‎달다 (dalda, “(of metal) to become heated”) + ‎구 (-gu-) → ‎달구다 (dalguda, “to heat (metal)”)

Although still very common in Korean, the causative/passive suffixes are no longer productive for forming new verbs. Verbs that do not already have a morphological causative or passive must employ auxiliaries:

• 게 하다 (-ge hada) for causatives
• 어지다 (-eojida) for passives