-을 때: When — the Moment / Situation

When	Form	Example
Stem ends in a consonant (not ㄹ)	-을 때	먹다 → 먹을 때 / 있다 → 있을 때
Stem ends in a vowel or ㄹ	-ㄹ 때	가다 → 갈 때 / 살다 → 살 때
Past situation (common twin)	-은/ㄴ 때	갔을 때 / 학생일 때

When

Form

Example

Stem ends in a consonant (not ㄹ)

-을 때

먹다 → 먹을 때 / 있다 → 있을 때

Stem ends in a vowel or ㄹ

-ㄹ 때

가다 → 갈 때 / 살다 → 살 때

Past situation (common twin)

-은/ㄴ 때

갔을 때 / 학생일 때

-을 때 builds a when… phrase — the moment or situation of an action.

저는 시간이 있을 때 요리해요 — when I have time, I cook. 때 is a time/occasion noun; the modifier links the verb to that slot. English when overlaps heavily with conditional -(으)면; Korean still chooses tools by job.

What it does — time/situation frame

바쁠 때 커피를 마셔요.
한국에 갈 때 연락해요.
혼자 있을 때 음악을 들어요.
주말에 시간이 있을 때 요리해요.

Hobby talk loves this frame: free time as a when slot for what you do. Noun + 때 also exists lexically (방학 때, 어릴 때); from verbs, use the modifier + 때.

Forms

Stem	Form
Consonant (not ㄹ)	-을 때
Vowel or ㄹ	-ㄹ 때

The -을/ㄹ modifier here often just links to 때 without a strong future claim. Do not over-read “future tense” into every 을 때.

Not -(으)면

Form	Job
-(으)면	if / when as a condition
-을 때	when as a time/situation phrase

시간 있으면 오세요.           condition — if you have time
시간 있을 때 요리해요.         situation — when I have time, I cook

Overlap in English when is huge. Ask whether you mean a condition for something to apply, or a time slot for a habit/event.

Past twin and progressive

You will also meet -았을 때 / -은 때 for finished situations (한국에 살았을 때). -았-/-었- lives in that past marking — keep tense mostly in one place rather than stacking -었- on every clause.

있을 때 is enough for “when I have…”. -고 있다 adds progressive when you need “while in the middle of…,” not as a default upgrade on every 때 phrase.

Practice rule: if you can replace the clause with “at the time when…,” -을 때 fits. If you mean “if this holds, then…,” check -으면.

Taught alongside this

On the jabi learning path, this appears in 저는 시간이 있을 때 요리해요 (I cook when I have time) — Beginner Korean 2, Unit 17, on the theme of hobby. These come with it:

Quick check

No sign-up, no score saved — just see if it stuck.

1. What does -을 때 mark?

2. -을 때 vs -(으)면?

3. 시간이 있을 때 요리해요 — correct reading?

Common questions

Is -을 때 always future?

The -을/ㄹ modifier here often just links to 때 without a strong future claim. Past scenes commonly use -았을 때 / -은 때 as well — learn -을 때 from this unit first.

있을 때 vs 있고 있을 때?

있을 때 is enough for 'when I have…'. go-itda adds progressive when you need 'while in the middle of…'.

Can I say 먹었을 때였어요 with double past everywhere?

Keep tense mostly in one place. Prefer 학생일 때 / 한국에 갔을 때 patterns rather than stacking every clause with -었-.

Noun + 때?

Yes: 방학 때, 어릴 때 (lexical). From verbs, use the modifier + 때.