In short

A causative says you made or let someone do something. Korean has three tools. A closed, memorized set of verbs adds an infix -이/히/리/기/우/구/추- to the stem: 먹다 (to eat) -> 먹이다 (meogida, to feed). For any other verb, attach -게 하다 to the stem: 자다 (to sleep) -> 자게 하다 (jage hada, to make/let sleep). And a Sino-Korean 하다-noun becomes causative by swapping 하다 -> 시키다: 공부하다 -> 공부시키다 (gongbusikida, to make someone study).

The rule

Step 1 - Three ways to build a causative

• Lexical - a fixed, memorized set of verbs takes one of the seven infixes -이/히/리/기/우/구/추- between the stem and 다. These are short and idiomatic but you must learn each one (see the table below).
• Periphrastic -게 하다 - fully productive: any verb stem + -게 하다 means make or let someone do it. This is the safe fallback when a verb has no lexical causative.
• 시키다 - for Sino-Korean action nouns (한자어): replace 하다 with 시키다. 청소하다 (to clean) -> 청소시키다 (to make someone clean).

Step 2 - The lexical affixes and the case frame

Attach the infix to the stem: 먹다 -> 먹이다, 입다 -> 입히다, 울다 -> 울리다, 웃다 -> 웃기다, 자다 -> 재우다, 늦다 -> 늦추다. The causee (the person made to act) is marked by the base verb’s type:

• Intransitive base -> the causee takes 을/를: 아이를 재워요 (aireul jaewoyo, put the child to bed), 차를 세워요 (chareul sewoyo, stop the car).
• Transitive base -> the base already owns a 을/를 object, so the causee takes 에게/한테: 아이에게 밥을 먹여요 (aiege babeul meogyeoyo, feed the child rice). You can never stack two 을/를 in a row.

Step 3 - -게 하다 and -게 만들다 (permissive vs coercive)

Verb stem + -게 하다 covers both “make” and “let”; the particle on the causee tilts the reading:

• Causee with 을/를 leans coercive - made: 동생을 울게 했어요 (dongsaengeul ulge haesseoyo, I made my sibling cry).
• Causee with 이/가 (or 에게) leans permissive - let: 동생이 놀게 했어요 (dongsaengi nolge haesseoyo, I let my sibling play).

-게 만들다 (make it so that) stresses bringing about a result or feeling, and works with adjectives too: 저를 웃게 만들어요 (jeoreul utge mandeureoyo, it makes me laugh), 방을 시원하게 만들어요 (makes the room cool).

Step 4 - 시키다 with 한자어

Many noun + 하다 verbs causativize by swapping in 시키다 (not every one - there is no *사랑시키다): 공부하다 -> 공부시키다, 준비하다 -> 준비시키다, 안심하다 -> 안심시키다 (to reassure someone) - and Step 2’s rule marks the causee here too, keyed to whether the 한자어’s own object is named: with none named the causee takes 을/를 (아이를 공부시켜요), and as soon as one is named it rises to 에게/한테 (아이들에게 방을 청소시켜요). Do not confuse it with plain 하다 (you do it yourself) or with 시키다 = “to order (food)”: 짜장면을 시켜요 (jjajangmyeoneul sikyeoyo, order jajangmyeon), the colloquial cousin of the more formal 주문하다.

Step 5 - Telling a causative from a passive (lesson 55)

The four infixes 이·히·리·기 also build the passive, so many forms overlap. Two signals resolve it:

• 우·구·추 are causative only - 재우다, 세우다, 늦추다 can never be passive.
• Read the case frame. A causative adds a causer and keeps (or adds) a 을/를 object; a passive turns the patient into the 이/가 subject and adds no new object. So 아이에게 밥을 먹이다 (feed, causative) vs 밥이 잘 안 먹혀요 (babi jal an meokyeoyo, the food won’t go down, passive). The genuinely ambiguous same-form verbs (보이다, 읽히다) are read the same way: 사진을 보여요 (shows a photo, causative) vs 산이 보여요 (the mountain is visible, passive). For the more formal “see to it that someone does,” Korean also uses -도록 하다 (see lesson 51).

Forms & patterns

The lexical causative infixes (stem -> causative -> 해요체):

The three strategies side by side:

How the causee is marked:

Examples

Common mistakes

• 아이를 밥을 먹여요. (Aireul babeul meogyeoyo.) -> 아이에게 밥을 먹여요. (Aiege babeul meogyeoyo.) - a transitive base already owns its 밥을, so the causee takes 에게; two 을/를 in a row is ungrammatical.
• 아이를 일찍 잤어요. (Aireul iljjik jasseoyo.) -> 아이를 일찍 재웠어요. (Aireul iljjik jaewosseoyo.) - 자다 (to sleep) is intransitive and cannot take a 를 object; to “put someone to sleep” use the causative 재우다.
• 아이에게 옷을 입어요. (Aiege oseul ibeoyo.) -> 아이에게 옷을 입혀요. (Aiege oseul ipyeoyo.) - 입다 is “wear (yourself)”; to dress someone else you need the causative 입히다 with the -히- infix.
• 엄마가 아이에게 방을 청소했어요. (Eommaga aiege bangeul cheongsohaesseoyo.) -> 엄마가 아이에게 방을 청소시켰어요. (Eommaga aiege bangeul cheongsosikyeosseoyo.) - plain 청소하다 means you do it yourself and has no slot for the person made to act (아이에게); to make someone do a 하다-action, swap in 시키다.
• 동생를 웃겼어요. (Dongsaengreul utgyeosseoyo.) -> 동생을 웃겼어요. (Dongsaengeul utgyeosseoyo.) - 동생 ends in a 받침, so the object particle is 을, never *를.

Tips

• 우·구·추 = always causative. The infixes 이·히·리·기 are shared with the passive (lesson 55), but 우·구·추 build causatives only - so 재우다, 세우다, 늦추다 can never be a passive. A quick disambiguation signal.
• Read the case frame, not the ending. 보이다 and 읽히다 are both causative and passive. If there is a 을/를 object and a causer, it is causative (사진을 보여요, shows a photo); if the patient is the 이/가 subject with no new object, it is passive (별이 보여요, the stars are visible).
• -게 하다 is the escape hatch. The lexical set is closed and must be memorized; when a verb has none, or you can’t recall it, stem + -게 하다 always works. Put 을/를 on the causee to lean toward “make,” 이/가 to lean toward “let.”
• 시키다 causativizes many 하다-nouns. Swap 하다 -> 시키다: 공부하다 -> 공부시키다, 청소하다 -> 청소시키다 - but not every one (no *사랑시키다). Just don’t mix it up with 시키다 “to order (food),” as in 커피를 시켜요.