The 되다 Passive: N이/가 되다, N하다 → N되다

Korean has thousands of verbs built on the pattern [Sino-Korean noun] + 하다: 사용하다 ("use"), 발견하다 ("discover"), 건설하다 ("build"), 시작하다 ("start"). Almost none of them has a fused suffix passive — there is no ×사용히다, no ×발견히다. So how do you say "it was used," "it was discovered"? You swap the 하다 for 되다. That one substitution — 하다 → 되다 — is the single most productive passive mechanism in the language, and it is the workhorse of formal, written, and news Korean. Master the 하다/되다 alternation and you unlock "be X-ed" for an enormous slice of the vocabulary at one stroke.

The mechanism: 하다 → 되다

되다 is a light verb meaning "to become / come to be / get done." Attached to a Sino-Korean action noun, it does exactly what the English passive does: it makes the noun's action happen to the subject, with no agent required. Where 하다 is the active ("do X"), 되다 is its passive/middle counterpart ("X is done / X happens").

Conjugating 되다 — get these five right

Because 되다 ends in the vowel-cluster 되, its conjugation trips learners up (and its spelling, 되 vs 돼, trips up native speakers). Here is the reference; the polite present is 돼요 (되 + 어요 → 돼요), and the formal present is 됩니다.

The written plain past 사용되었다 is what you meet in newspapers and reports; the spoken contraction is 사용됐다/사용됐어요. Both are correct — one is register, not a different grammar. Getting 돼 vs 되 right in writing is its own headache, addressed on the 되다/돼요 spelling page.

Why 되다 is the passive escape hatch

Here is the reframing for English speakers. English builds every passive the same way — be + past participle — so "be used," "be discovered," "be built" all look alike. Korean's suffix passives (열리다, 보이다, 잡히다) are a closed set: a verb either has one or it doesn't, and the vast Sino-Korean 하다-class doesn't. 되다 is what fills that hole. It means that once you know a noun's 하다-verb, you very often get its passive for free by swapping in 되다 — no new stem to memorize, no suffix to guess.

This productivity is why several 되다 forms are among the earliest passives learners meet, long before the suffix passives feel comfortable: 시작되다 ("begin") and 걱정되다 ("be worried / worrying") show up in beginner textbooks precisely because they are so common.

Notice 걱정되다 and 시작되다 aren't "passive" in the strict "acted upon by an agent" sense — they're closer to a middle/inchoative ("come to be worried," "come to begin"). 되다 straddles passive and inchoative, which is the same family resemblance it shares with -게 되다 and becoming. Don't force every 되다 into an English "was X-ed"; sometimes "gets," "becomes," or "ends up" fits better.

The valency flip: 하다 takes an object, 되다 takes a subject

The most important structural consequence: 하다 is transitive (it needs an object, marked 을/를), while 되다 is intransitive (its patient becomes the subject, marked 이/가). Watch the particles switch:

The full mechanics of this object-to-subject shift — what linguists call the valency change — are on the 하다/되다 valency page. For now, the practical takeaway is: the moment you go from 하다 to 되다, the thing that was the object (을/를) becomes the subject (이/가).

Standalone 되다: "become" and "work/be OK"

되다 also lives on its own, without a Sino-noun in front, in two everyday meanings that you should not confuse with the passive. First, N이/가 되다 = "become a [noun]" (의사가 되다 — see the three routes of becoming). Second, bare 되다 = "to work / be possible / be allowed," most famously in the negative 안 돼요 ("it doesn't work / no good / not allowed").

Common Mistakes

1. Keeping 하다 where the meaning is intransitive "began." 시작하다 needs an object (someone starts something); "the meeting began by itself" is 시작되다.

2. The double passive 되어지다. 되다 is already passive; adding -어지다 stacks a second one.

3. Marking the 되다 subject with 을/를. The 되다 passive is intransitive; its patient is a subject (이/가).

4. Misspelling 돼요 as ×되요. The polite present is 되 + 어요 → 돼요, never ×되요.

Key Takeaways

• The 되다 passive turns a Sino-Korean 하다-verb into "be/get X-ed" by swapping 하다 → 되다: 사용하다 → 사용되다, 발견하다 → 발견되다, 시작하다 → 시작되다.
• It's the passive escape hatch for the thousands of 하다-verbs that have no fused suffix passive (×사용히다 doesn't exist) — the highest-leverage passive rule in Korean, dominant in formal and written register.
• 되다 straddles passive and inchoative — some forms (걱정되다, 시작되다) mean "come to be" rather than "be acted upon."
• 하다 is transitive (object 을/를); 되다 is intransitive (subject 이/가) — the particles flip.
• Beware the double passive ×되어지다 and the ×되요 spelling; and don't confuse the passive with standalone 되다 = "become / work."