며칠 vs 몇 일: The Spelling Trap

Almost every Korean question about "how many" is built the same way: the question-word 몇 ("how many / what") sits in front of a counter, written with a space between them — 몇 시 (what time), 몇 명 (how many people), 몇 개 (how many things). There is exactly one place where this transparent little machine breaks down, and it happens to be one of the highest-frequency questions a learner ever asks: the date. "What's the date?" and "how many days?" are both 며칠 — written solid, spelled irregularly, and marked wrong by Korean orthography if you write the logical-looking ×몇 일. This page nails down that single exception so it never trips you up again.

One word, two meanings

며칠 covers two English questions that, in Korean, turn out to be the same word. Which one is meant is decided entirely by context — the verb and the rest of the sentence tell you whether someone is asking about a calendar date or a duration.

In the first two, 며칠 asks which date on the calendar; in the third, it asks how many days as a span. Nothing about the word changes — 며칠이에요? leans toward "what date," while 며칠 followed by a verb of duration (걸리다 "take," 있다 "stay," 되다 "become") leans toward "how many days." Context does all the disambiguating.

Notice that last one: 며칠 also does duty as the vague "a few days," exactly the way English "a couple of days" can be an answer as well as a question. 며칠 후에 ("in a few days"), 며칠 전에 ("a few days ago"), 며칠 동안 ("for a few days") are everyday set phrases.

The spelling rule: 며칠, never ×몇 일

Here is the trap. The word obviously comes from 몇 ("how many") + 일 ("day," the Sino-Korean counter you already use in dates like 15일). Every fibre of your grammatical instinct says it should be written ×몇 일, spaced, just like 몇 월 and 몇 시. It isn't. Korean's official spelling standard (한글 맞춤법 §27) fixes it as the single fused word 며칠, and 몇 일 is counted as a straight-up misspelling — the kind that costs points on a 받아쓰기 dictation and looks wrong to any literate Korean.

Why the spelling refuses to show its own seams

This is not a random decree — there's a real phonological reason, and understanding it makes the spelling stick. If 몇 and 일 were still two live pieces glued together, the result would sound a particular way. Compare 몇 년 ("how many years"), pronounced [면년], and 몇 월 ("what month"), pronounced [며둴]. In both, the ㅊ of 몇 collapses to a plain [t]-type stop before it meets the next syllable. By that logic 몇 + 일 ought to come out as [면닐] or [며딜].

But nobody says that. Everyone says [며칠], with the ㅊ fully intact and liaised straight onto the following vowel. That pronunciation simply cannot be reconstructed from 몇 + 일 — the seam has healed over. So Korean spelling stops pretending the word is two morphemes and writes it the way it actually sounds: 며칠. The irregular spelling is honest; it's the "logical" 몇 일 that would be a lie about the pronunciation.

The counters that keep 몇 spaced

The reason 며칠 feels so treacherous is that it is the lone exception in a family of perfectly regular, perfectly spaced 몇-phrases. In every other case, 몇 is a determiner standing on its own, a space away from its counter, and it means "how many / what."

So the mental rule is clean: spell 몇 + counter with a space everywhere — except the date, which is the single solid word 며칠. (The bracketed forms above show the real pronunciations, several of which tense or nasalize; the romanization line keeps each spaced word separate, so it doesn't carry those cross-word sound changes.)

The clash is sharpest when the two collide in one breath — asking for a full date, you say 몇 월 (spaced) and 며칠 (solid) side by side:

며칠 vs 무슨 요일: date vs day-of-week

One more distinction worth flagging, because English blurs it. 며칠 asks for the date (the number — the 3rd, the 15th). To ask which day of the week (Monday, Tuesday…), Korean uses a different question entirely: 무슨 요일 ("what day of the week"). Don't reach for 며칠 when you mean Monday.

Answering a 며칠 question about a date, incidentally, you switch back to the ordinary spaced spelling: the 15th is 십오 일 (Sino number + 일), written 일 the normal way. The fusion is only in the question word 며칠. The full run of dates lives on the year-month-day page, and the weekday names on the days-of-the-week page.

Common Mistakes

1. Writing ×몇 일 for the date. This is the error — the whole reason this page exists. The word is one solid unit.

• ✗ 오늘 몇 일이에요?
• ✓ 오늘 며칠이에요? — oneul myeochirieyo — "What's the date today?"

2. Fusing 몇 월, 몇 시, 몇 명 by analogy. The fusion runs the other direction: only the date word is solid; the rest stay spaced.

• ✗ 며칠월, ×몇시, ×몇명
• ✓ 몇 월 (며둴), 몇 시 (멷씨), 몇 명 (면명) — all spaced

3. Using 며칠 to ask the day of the week. 며칠 is the calendar number; the weekday is 무슨 요일.

• ✗ 오늘 며칠이에요? (when you want to know it's Tuesday)
• ✓ 오늘 무슨 요일이에요? — oneul museun yoirieyo — "What day of the week is it?"

4. Over-spelling the answer as ×며칠 for a specific date. The answer to "what date" is a plain Sino number + 일, not another 며칠.

• ✗ 오늘은 며칠 일이에요.
• ✓ 오늘은 오 일이에요. — oneureun o irieyo — "Today is the 5th."

5. Assuming 며칠 always means "how many days." It just as often means "what date," and — as a bonus — it can mean the vague "a few days." Let the verb decide.

• 며칠 걸려요? = "how many days does it take?" (duration)
• 오늘 며칠이에요? = "what's the date?" (calendar)
• 며칠 후에 = "in a few days" (vague quantity)

Key Takeaways

• 며칠 is a single solid word meaning both "what date?" and "how many days?" — context (usually the verb) tells the two apart.
• The transparent-looking ×몇 일 is a misspelling, not an alternative. Spell it 며칠, always.
• The reason is phonological: 몇 + 일 would sound like [면닐] or [며딜] (compare 몇 년 [면년], 몇 월 [며둴]), but the word is actually [며칠] — a pronunciation you can't rebuild from the parts, so the spelling follows the sound.
• Every other 몇-phrase stays spaced: 몇 월, 몇 시, 몇 명, 몇 개. 며칠 is the lone fused exception.
• To ask a full date, pair the spaced 몇 월 with the solid 며칠: 몇 월 며칠. For the weekday, switch to 무슨 요일.