“〜yoshi mo nai”: No Way at All to 〜 (a classical, literary expression) [JLPT N1]

Content by NTJ Kuma · Nihongo to Japan editorial team · Updated July 27, 2026

「知るよしもない」 — there's no way, no means, to know — with a wistful, literary sigh.

「彼の真意は、知る由もない」 — no way to know, no means of knowing

To want to know something, yet have not a single clue, not one means — 「当時の彼の心境は、今となっては知る由もない (his state of mind at the time, now there's no way to know).」 「〜よしもない」 = there's no way to ～, no means of ～, cannot possibly ～. It's a classical, literary written expression. This guide clarifies its core of “not even a means／clue,” that “由（よし）= means,” separating it from the close 「ようがない.」

Core: no way to ～, not even a means (clue) to ～ (cannot possibly ～)

「verb dictionary form ＋ よしもない（由もない）」 means “there's no way to ～, not even a means／method／clue to ～, cannot possibly ～” — not even a method, means, basis for doing something:

• 彼が今どこにいるのか、知る由もない (where he is now, there's no way to know).
• 真相は、もはや確かめるよしもない (the truth, there's no longer any way to verify).
• 何が起きたのか、当事者でない私には知るよしもなかった (what happened, I, not being involved, had no way to know).

Feel: the core is “not even a (means to do something) method, means, clue = no way to ～, cannot possibly ～.” 「由（よし）」 here means “method, means, reason” (not 「よし = good」!), and 「由もない」 = “not even a means.” It's a classical, literary, written expression, with a solemn, refined feel, most common in 「知る由もない (no way to know)」「確かめるよしもない (no way to verify).」 In English: “no way to ～, no way of knowing, not even a means to ～.”

How it attaches

Example sentences

• 見知らぬ土地で、頼る由もなく、彼は途方に暮れた。(In an unfamiliar land, with nothing to rely on, he was at a loss.)
• 亡き祖父が何を思っていたか、今では知る由もない。(What my late grandfather was thinking, now there's no way to know.)
• 遠く離れた故郷の様子は、うかがい知る由もなかった。(The state of my far-off hometown, I had no way to learn.)
• 手がかりもなく、真相に迫るよしもない。(With no clues, there's no way to close in on the truth.)
• 匿名の投書では、送り主を突き止めるよしもない。(With an anonymous letter, there's no way to trace the sender.)

⚠️ Where learners slip up

① 「由（よし）」 = method, means, reason; don't misread it as 「よし (good).」 This is the first hurdle. 「よしもない」's 「よし,」 written in kanji as 「由,」 means “method, means, clue, reason” — not 「よし (good, OK)」! So 「知る由もない」 = “not even a method (to know)” = “no way to know,” not “knowing isn't good.” 「由（よし）」 is a somewhat archaic word for “means, method, reason (origin).” Test: 「〜よしもない」's 「よし」 = 「由 (method, means, reason)」; 「〜由もない」 = “not even a means／clue (to do something) = no way to ～,” unrelated to 「good (よし).」

② The core is ‘not even a means／clue = no way to ～,' mostly with 知る／確かめる etc. This is 「よしもない」's core feel. It means “not even a (means to do something) method, means, basis, clue = no way to ～, cannot possibly ～,” most often with 知る (know)／確かめる (verify)／うかがい知る (learn)／突き止める (pin down) — “know, seek” type verbs: 知る由もない (no way to know — not even a means to know), 確かめるよしもない (no way to verify). It stresses “because there's no method／clue at all, one absolutely cannot (know／verify).” Test: to say “(not even a method／clue,) no way to ～, cannot possibly ～” → よしもない (mostly with 知る／確かめる).

③ It's a classical, literary, written expression; not used in everyday speech. This is the register point. 「よしもない（由もない）」 is a classical, literary, written expression, with a solemn, refined feel, mostly for literature, solemn narration, writing. Everyday speech almost never uses it — for “no way to know,” speech uses 「知りようがない」「知る方法がない」「知る手段がない,」 not 「知る由もない」 (which sounds stilted). Test: to say “no way to ～” in literature, solemn writing → よしもない (refined); for everyday → use 〜ようがない／方法がない.

④ Separate it from 「ようがない」 — よしもない is more classical (mostly with 知る／確かめる), ようがない is more general. Both express “(want to but) no way to ～,” very close, differing in register and collocation. 「〜よしもない」 = no way to ～, not even a means (classical, literary, mostly with ‘know, seek' type verbs like 知る／確かめる): 真相を知るよしもない (no way to know the truth — not even a means to know). It's more classical, refined, and most often with ‘know, seek' type verbs (知る／確かめる). 「〜ようがない」 = want to but no way to, cannot ～ (more general, precedes a verb masu-stem, see 〈ようがない〉): 連絡先が分からないので、連絡しようがない (I don't know the contact, so there's no way to contact — general), 直しようがない (no way to fix it). It's more general, spoken and written, preceding a verb masu-stem (連絡し／直し), able to take various verbs. Difference: 「よしもない」 classical, literary, mostly with 知る／確かめる (no way to ～); 「ようがない」 more general, precedes a masu-stem, takes various verbs (want to but no way to, see 〈ようがない〉). Test: to classically, refinedly say “no way to (know／verify) ～” → よしもない (知る由もない); to generally say “(want to but) no way to ～” → ようがない (連絡しようがない).

🔄 Compare: よしもない／ようがない／すべがない／術がない

💡 Learning tip

「〜よしもない（由もない）」 = no way to ～, not even a means to ～, cannot possibly ～ — three points: ①「由（よし）」 = method, means, reason (don't misread as 「よし = good」! 由もない = not even a means); ② the core is ‘not even a means／clue = no way to ～,' most often with 知る／確かめる (知る由もない = no way to know); ③ it's a classical, literary, written expression; everyday speech uses 「ようがない」 (see 〈ようがない〉). This expression has a real classical, literary lingering — 「今となっては知る由もない」 renders, resonantly, that helpless, desolate feel of “now, there's not even a way to know, it can only remain forever a mystery.” To refinedly, solemnly say “no way to know, no way to verify,” 「知る由もない／確かめるよしもない」 has the most flavor; for everyday speech, use 「知りようがない.」 (Note: 「由」 is read よし, meaning “means,” not “good.”)

❓ Common questions

Q: What does the 「由（よし）」 of 「知る由もない」 mean? Is it ‘good'?

Not ‘good'! 「由（よし）」 here means ‘method, means, clue, reason.' This is the most misread point. The 「由」 of 「知る由もない」 is read 「よし,」 a somewhat archaic word meaning “method, means, basis, reason (origin)” — entirely not 「よし (good, OK)」! So 「知る由もない」 = “not even a method (to know)” = “no way to know, cannot possibly know,” not “knowing isn't good” or “not sure if good.” Likewise: 「確かめるよしもない」 = “not even a means (to verify)” = “no way to verify,” 「なす由もない」 = “not even a means (to do)” = “at a loss.” This use of 「由（よし）」 for “method／means／reason” is a classical residue, surviving mainly in literary expressions like 「知る由もない」「〜由もない」 (separately, 「〜の由（よし）」 can also mean “I hear ～, they say ～,” as in 「ご健勝の由、何よりです,」 that being “reason, hearsay”). Test: 「〜よしもない／由もない」's 「由（よし）」 = “method, means, reason” (not “good”); the whole 「由もない」 = “not even a means = no way to ～.” ⚠️Don't see 「よし」 and assume “good” — here it's the kanji 「由 (means).」

Q: What's the difference between 「知る由もない」 and 「知りようがない」?

Close in meaning (both “no way to know, can't know”), differing in ‘register' and ‘collocation.' 「〜よしもない（由もない）」 = no way to ～ (classical, literary, written, mostly with 知る／確かめる): 「知る由もない」 is a classical, refined, solemn phrasing, with literary lingering, mostly for solemn narration, literature, writing, and most often with ‘know, seek' type verbs (知る／確かめる／うかがい知る): 当時の真相は、今となっては知る由もない (the truth of the time, now there's no way to know — refined, with a desolate lingering). It's more written, weighty. 「〜ようがない」 = want to but no way to (more general, precedes a verb masu-stem, see 〈ようがない〉): 「知りようがない」 is a more general, spoken-and-written phrasing, preceding a verb masu-stem (知り／連絡し／直し), able to take various verbs, plainer: 連絡先がないので、知りようがない (with no contact, there's no way to know — general, plain). Difference: 「知る由もない」 classical, refined, written (with literary lingering, mostly with 知る／確かめる); 「知りようがない」 more general, plain (spoken and written, precedes a masu-stem, takes various verbs, see 〈ようがない〉). Test: to classically, refinedly, with lingering say “no way to know” → 知る由もない; to generally, plainly say “(want to but) no way to know” → 知りようがない. Close in meaning, 「由もない」 more literary and resonant, 「ようがない」 more everyday and general. So to write “no way to know” in literature, solemnly, use 「知る由もない,」 for everyday “no way to know” use 「知りようがない.」

🖊️ Practice Questions (5)

Q1. 「彼がどこにいるか、知る___。」(There is simply no way to know where he is — a literary tone)

(A) よしもない　(B) ようがない　(C) ことができない　(D) よしがある

Q2. 「よしもない」の意味に最も近い現代語は？

(A) 〜してはいけない

(B) 〜する方法が全くない（ようがない・手段がない）

(C) 〜したくない

(D) 〜するかもしれない

Q3. 「状況を確認する___まま、時間が過ぎた。」(With no way at all to confirm the situation, time passed)

(A) よしもない　(B) ようがない　(C) ことができない　(D) よしがない

Q4. 「よしもない」が最も自然に使われる場面は？

(A) 日常会話で「なんか方法ないよね」と言う時

(B) 文学作品や書面語で感情のこもった「cannot 〜 at all」を表す時

(C) ビジネス会話で「できません」と断る時

(D) 命令文で「するな」を表す時

Q5. 「真相を確かめる___のまま、謎は残った。」(With no way at all to verify the truth, the mystery remained)

(A) よし　(B) よしがない　(C) よしもない　(D) よしがある

Answer Explanations

1. (A) よしもない ──「彼がどこにいるか知るよしもない」(there is no way to know where he is) = a classical / literary strong sense of "utterly no means." (B) ようがない is more modern, (C) ことができない is the most colloquial, (D) よしがある is the opposite meaning.

2. (B) ── よしもない ≒ ようがない (no way / no means to 〜); in modern Japanese, ようがない is its replacement expression.

3. (A) よしもない ──「状況を確認するよしもないまま、時間が過ぎた」(with no way to confirm the situation, time passed) = a classical / literary lament; the other options don't fit this reflective context.

4. (B) ── よしもない is classical / written language, most natural in literary works and written text, used to express the lament of "there is simply no way to 〜."

5. (C) よしもない ── 「真相を確かめるよしもない」(there is no way to verify the truth) = a typical use of よしもない: classical / literary / lamenting.