Embedded Decisions: -기로 하다 vs -(으)ㄹ지

English uses one verb — decide — for two very different mental acts: you can decide to do something (the matter is now settled) or you can be trying to decide whether to do it (the matter is still open). Korean splits these into two grammatical frames that look nothing alike, and choosing the wrong one tells your listener the opposite of what you mean. A settled resolution embeds with -기로 하다; an unresolved deliberation embeds with -(으)ㄹ지. This page teaches them side by side, because the contrast is the whole point.

-기로 하다: the decision is made

The frame [verb stem] + -기로 하다 reports a decision that has already been reached. The activity nominalizer -기 turns the verb into a noun ("the doing of X"), the particle 로 adds the sense "as / in the direction of," and 하다 ("do/make") completes it — literally something like "I made it as [the doing of X]." The result is idiomatic and extremely common: it is how Koreans say "I('ve) decided to."

Notice the past tense 했어요. Because the decision is a completed event, -기로 하다 almost always appears in the past — you made the decision, so you report it as done, even when the action itself lies in the future.

하다 can become 결정하다, 약속하다, 결심하다

The 하다 slot is really a placeholder for "settle it," so you can swap in a more specific verb of deciding, promising, or resolving. The -기로 part never changes.

• 결심하다 / 결정하다 — "resolve / decide" (a firmer, more deliberate ring).
• 약속하다 — "promise" (a commitment made to someone).
• Plain 하다 — the neutral default, "decide to."

Soft self-resolution

Beyond reporting group plans, -기로 하다 does a gentle, personal "I've decided to ~ (from now on)." It is how you announce a resolution about your own behavior without sounding preachy.

-(으)ㄹ지: the decision is still open

The frame [verb stem] + -(으)ㄹ지 embeds a question you are still turning over. It is built from the prospective / future attributive -(으)ㄹ plus the bound noun 지, so it literally frames "whether / what / how [one is] to do." Use -ㄹ지 after a vowel or ㄹ (갈지, 할지) and -을지 after a consonant (먹을지, 있을지). It slots in front of verbs of wondering, worrying, and not-yet-knowing: 모르다, 고민이다/고민하다, 생각하다, 결정하다 (still deciding what).

Because the matter is unresolved, -(으)ㄹ지 pairs naturally with a wh-word (어디, 뭐, 어떻게, 언제) or with the yes/no frame below. The main clause names the state of deliberation, not a conclusion.

The yes/no version: -(으)ㄹ지 말지

To deliberate a straight yes-or-no — "whether to do it or not" — Korean repeats the pattern with the negative verb 말다: -(으)ㄹ지 말지 ("whether to do or to refrain"). This is the go-to phrase for an agonized on-the-fence decision.

Here 결정 appears with -(으)ㄹ지 말지 — and crucially it is still an open deliberation ("haven't decided whether"), which is exactly why it takes -(으)ㄹ지 and not -기로.

Why they can't be swapped

Line the two up and the logic is transparent:

-기로 points toward a chosen action — the 로 is a direction you have committed to. -(으)ㄹ지 wraps the action in a question mark — the 지 leaves the outcome hanging. So the same underlying event, 가다 ("go"), lands in opposite frames depending on where your mind is: 가기로 했어요 means the ticket is as good as booked, while 갈지 모르겠어요 means you have no idea yet. This is the English decide TO vs decide WHETHER to split, made grammatical.

The -(으)ㄹ지 frame is closely related to the indirect-question ending -는지 ("[I wonder] whether/what ~") used for embedded facts and questions about other people's situations; see embedded questions with -는지. The difference is that -(으)ㄹ지 leans on the prospective -(으)ㄹ, so it is naturally about a course of action still to be chosen, typically one's own. For the standalone decision-marking -기로 하다 as a modality pattern, and for the nominalizer -기 that feeds it, see their own pages.

Common Mistakes

Mistake 1 — Using -(으)ㄹ지 하다 for a firm decision. English "decide" tempts learners to build ×-(으)ㄹ지 하다, but a made decision needs -기로 하다.

Mistake 2 — Using -기로 for a still-open question. If you are genuinely undecided, -기로 (which claims a settled choice) contradicts you; use -(으)ㄹ지.

Mistake 3 — Dropping the 말지 in a yes/no deliberation. For a straight "whether or not," Korean wants the paired -(으)ㄹ지 말지; a bare -(으)ㄹ지 with a yes/no verb sounds unfinished.

Mistake 4 — Putting -기로 하다 in the present for a set plan. A finished decision is reported in the past.

Key Takeaways

• -기로 하다 = a settled decision ("decide TO"): -기 (nominalizer) + 로 (direction) + 하다. Swap 하다 for 결심하다 / 결정하다 / 약속하다 to sharpen it, and expect the past tense (했어요).
• -(으)ㄹ지 = an open deliberation ("whether / what to"): prospective -(으)ㄹ + 지. It rides with 모르다, 고민이다, 생각 중이다 and wh-words.
• -(으)ㄹ지 말지 is the yes/no version ("whether to ~ or not").
• Mixing them flips settled and unsettled — the single most reliable check is whether the matter is decided yet.