A word expressing hypothetical conditions, naturally used in everyday conversation
When to use
casual conversation, friendly hypothetical, informal writing
The nuance
Primarily used in casual, spoken contexts, giving a light and friendly tone
만약 (man-yak, manyak) · 만일 (man-il, manil)
Both 만약 and 만일 express conditional 'if,' but 만약 is more casual and 만일 fits formal or written contexts better.

One lane per word — no nested boxes, just the gist.
A word expressing hypothetical conditions, naturally used in everyday conversation
When to use
casual conversation, friendly hypothetical, informal writing
The nuance
Primarily used in casual, spoken contexts, giving a light and friendly tone
A word expressing hypothetical conditions, mainly used in formal or written language
When to use
official documents, news articles, formal speeches
The nuance
Mainly used in formal or literary contexts, conveying a formal and serious tone
만약 내일 비가 오면 집에 있을 거예요.
man-yak nae-il bi-ga o-myeon jip-e iss-eul geo-ye-yo., man yak nae il bi ga o myeon jip e iss eul geo ye yo.
A correct example of 만약 used naturally in casual conversation.
만일 내일 비가 오면 집에 있을 거예요.
man-il nae-il bi-ga o-myeon jip-e iss-eul geo-ye-yo., man il nae il bi ga o myeon jip e iss eul geo ye yo.
An appropriate example of 만일 used in a formal context.
만약 내일 회의가 있으면 참석할게요.
man-yak nae-il hoe-ui-ga iss-eu-myeon cham-seok-hal-ge-yo., man yak nae il hoe ui ga iss eu myeon cham seok hal ge yo.
A natural sentence using 만약 in a friendly context.
만일 내일 회의가 있으면 참석할게요.
man-il nae-il hoe-ui-ga iss-eu-myeon cham-seok-hal-ge-yo., man il nae il hoe ui ga iss eu myeon cham seok hal ge yo.
A suitable example of 만일 used in a formal situation.
만일 친구와 영화 보러 갈 거야?
man-il chin-gu-wa yeong-hwa bo-reo gal geo-ya?, man il chin gu wa yeong hwa bo reo gal geo ya?
만일 sounds awkward in informal, friendly questions; 만약 should be used instead.
만약 공식 발표에서 이 표현을 쓰세요.
man-yak gong-sik bal-pyo-e-seo i pyo-hyeon-eul sseu-se-yo., man yak gong sik bal pyo e seo i pyo hyeon eul sseu se yo.
In official announcements, the formal 만일 is more appropriate.
만약 사고가 나면 즉시 연락하세요.
man-yak sa-go-ga na-myeon jeuk-si yeon-rak-ha-se-yo., man yak sa go ga na myeon jeuk si yeon rak ha se yo.
A natural use of 만약 in everyday warning phrases.
만일 사고가 나면 즉시 연락하세요.
man-il sa-go-ga na-myeon jeuk-si yeon-rak-ha-se-yo., man il sa go ga na myeon jeuk si yeon rak ha se yo.
An appropriate example of 만일 in official documents or notices.
Which word is natural in casual talk with friends?
Which word fits conditional expressions in news articles?
Which sentence correctly uses '만일' with a friend?