-(으)ㄹ 것이다: Will / Intend To / Probably

-(으)ㄹ 것이다 is the workhorse Korean future — the ending you will hear and use more than any other for talking about what lies ahead. In everyday speech it almost always shows up contracted as -(으)ㄹ 거예요 (polite) or -(으)ㄹ 거야 (casual), with -(으)ㄹ 것입니다 kept for formal announcements. What English speakers need to get straight from the start is that this single form does two quite different jobs, and which one you hear depends entirely on the subject of the sentence: with a first-person "I/we" it states a plan, and with a third-person or non-human subject it states a guess. Same six-letter ending, two meanings, disambiguated by who is doing the verb.

The shape

The -(으)ㄹ part is the prospective modifier (the same one behind -(으)ㄹ게요 and -(으)ㄹ래요), and 것이다 is the bound noun 것 ("thing/fact") plus the copula 이다 — literally "it is a thing that will…". It attaches to verbs and adjectives alike, splitting by the final sound of the stem:

After a noun it uses the copula's -(이)ㄹ: 학생 → 학생일 거예요 ("is probably a student"). For the full formation drill, see the future -(으)ㄹ 것이다 tense page; this page is about what it means.

Job 1 — Intention / plan (first-person subject)

Put yourself in the subject slot and -(으)ㄹ 거예요 declares what you have decided to do. It is a flat, neutral statement of a plan — you are simply informing the listener of your intention, not promising anything to them (that distinction is the whole point of the next section).

In casual speech the same plan drops 요 to 거야:

Job 2 — Conjecture / prediction (third-person or non-volitional subject)

Now swap in a he/she/they, the weather, or any subject that cannot form intentions, and the exact same ending flips to "probably will / must be." Nothing about the form changes — the grammar reads the subject and reinterprets accordingly. This is the reading textbooks most often underplay, and it is enormously common in real Korean.

Notice the third one: -(으)ㄹ 거예요 stacks happily on a past stem (도착했을 거예요, "probably arrived"). A guess can point backwards — "it must have happened already" — which a plan obviously never can. That past-tense conjecture is a dead giveaway that you are in Job 2.

Why English hides this

English keeps these two ideas in separate words: "I am going to study" (plan) versus "he probably will not come" (guess). Korean folds both into -(으)ㄹ 거예요 and lets the subject do the sorting that English does with will versus probably will. So when you translate out of Korean, you supply "probably/must" for the conjecture reading even though there is no word for it in the sentence — the third-person subject is carrying that meaning silently. And when you translate into Korean, you do not add a word for "probably"; 올 거예요 already says it. Learners who reach for 아마 ("probably") every time are welcome to — it reinforces the guess reading — but the ending alone already carries it.

-(으)ㄹ 거예요 vs. -(으)ㄹ게요: a plan you announce vs. a promise you give

This is the contrast that trips up almost every learner, because English "I'll do it" covers both. The difference is who the sentence is aimed at:

• -(으)ㄹ 거예요 is a neutral declaration. You are stating your plan (or predicting an outcome) to the air, as information. It is not addressed to the listener as a commitment.
• -(으)ㄹ게요 is an interactive promise. It responds to the listener and hands them your action — "I'll do it, so count on me." (Full treatment on the -(으)ㄹ게요 page.)

The practical fallout: when someone asks you for a favor, answering with 도와줄 거예요 ("I'm going to help") sounds oddly detached, as if you were reporting a pre-existing plan rather than agreeing to their request. The cooperative answer is the promise, 도와줄게요. Reserve -(으)ㄹ 거예요 for informing, not for committing.

-(으)ㄹ 거예요 vs. -겠-: settled plan vs. on-the-spot resolve

Korean's other future marker, -겠-, is heavier and more immediate. Where -(으)ㄹ 거예요 states a plan you have already formed, -겠- announces a resolve made in the moment, and it dominates fixed, formal, first-person declarations.

Compare 출발할 거예요 ("I'm going to set off / I plan to set off") — flatter, more of a scheduled plan. In a job interview, at a ceremony, or in a public promise, Koreans reach for 하겠습니다; for describing next weekend's itinerary they reach for 할 거예요. There is a dedicated -겠- vs. -(으)ㄹ 것이다 comparison if you want them side by side.

In writing and formal speech: -(으)ㄹ 것입니다

The uncontracted 것입니다 belongs to formal registers (formal) — news scripts, official notices, speeches, and forecasts read aloud. It carries the same two readings (plan or prediction) as the spoken 거예요.

Common Mistakes

1. Using -(으)ㄹ 거예요 as a promise in reply to a request. A responsive commitment needs -(으)ㄹ게요.

2. Missing the conjecture reading with a third-person subject. 그 사람은 바쁠 거예요 is not "that person will be busy (a plan)" — people don't plan to be busy — it is "that person is probably busy."

3. Writing it 거에요 or gluing the space. The correct spelling is 거예요, and 거 is spaced off the modifier.

4. Adding 아마 to a plan. 아마 ("probably") belongs with the guess reading, not your own firm plan. ×저는 아마 갈 거예요 for "I'm definitely going" contradicts itself; drop 아마, or keep it only if you genuinely mean "I'll probably go."

5. Over-marking the future. Korean often uses the plain present for scheduled events (내일 시험 봐요, "I have an exam tomorrow"). You don't need -(으)ㄹ 거예요 on every future sentence — reach for it when you're stating a genuine plan or prediction, not a fixed timetable.

Key Takeaways

• -(으)ㄹ 거예요 / 거야 / 것입니다 is the everyday future, and its meaning is set by the subject.
• First person → plan/intention ("I'm going to…"); third person or non-volitional → conjecture ("probably will / must be…"), and it can even look backward: 도착했을 거예요, "probably arrived."
• It informs; it does not promise. For a commitment aimed at the listener, use -(으)ㄹ게요.
• It is a settled plan or prediction; on-the-spot formal resolve is -겠- (출발하겠습니다).
• Spell it 거예요 and keep the space before 거.