adverbial N1 uncommon writtenliterary
いかに — how (much) ~ / however ~
いかに
Meaning
① how (much) ~ (degree exclamation/question): how ~ / just how ~ — emphasises the degree of something, often in 〜か embedded form
② however much ~ (concession): however much ~ / no matter how ~ — paired with 〜ても / 〜とも, the situation holds regardless of degree
Key sentence
① how (much) ~ (degree exclamation/question)
この発見がいかに重要か、誰もが知っている。
Everyone knows just how important this discovery is.
② however much ~ (concession)
いかに優秀でも、努力を怠れば成功しない。
However talented you are, you won't succeed if you neglect to work hard.
Formation
| Attaches to | Form | Example |
|---|---|---|
| Before an adjective/verb; concession with 〜ても / 〜とも | いかに + A/V（＋か / ても） | いかに難しいか / いかに〜ても |
When: Formal/literary. The 'how much' sense is common in embedded 〜か clauses; the concessive needs a following ても/とも.
Examples
① how (much) ~ (degree exclamation/question)
彼がいかに苦労したかは、想像に難くない。
It's not hard to imagine how much he suffered.
② however much ~ (concession)
いかに急いでも、締切には間に合わないだろう。
No matter how much we hurry, we probably won't make the deadline.
Easily confused with
どう どう is the everyday 'how / in what way'; いかに is the literary adverb stressing *degree* ('just how ~') or, with ても, 'however much ~'. Register, not meaning, is the main split. どんなに〜ても Same concessive force 'no matter how (much) ~', but どんなに〜ても is everyday spoken; いかに〜ても/とも is its formal-literary equivalent. いかなる いかに is an adverb (modifies a verb/adjective: いかに難しいか); いかなる is an adnominal (modifies a noun: いかなる問題も). Same 如何 root, different attachment.
Notes
- The literary set phrase いかにも means 'indeed / truly / how very ~' and is a separate idiom from this degree/concession いかに.
See いかに in real sentences
Jengo shows いかに the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.
Study it in JengoSources Compiled with reference to A Dictionary of Advanced Japanese Grammar.