哪裡…grammar point · tier 4 · rhetorical 哪裡(知道)… (how was I to know / who would have guessed)
哪裡 set in front of a verb of knowing or expecting denies that the knowing ever happened, and flags the clause that follows as a turn no one saw coming: how was I to know that…; who would have guessed that….
字源 FORM what the parts do
哪 carries the open question: 那 gives the sound, 口 the mouth that asks it. 裡 (里 for sound) makes 哪裡, the slot a place answer would fill. Set before a verb of knowing, that place-slot is emptied of any real where and asks the knowing instead: from what spot could I have known, when no such spot exists?
故事 STORY a scene to remember it by
A door swings open onto a scene the watcher had counted out; the mouth that would have asked "from where?" finds no spot it could have stood to see this coming.
You laid out what you set out to do, then the world turned the other way, and you want to say there was no vantage from which you could have known.
序 · The move
1State the plan or settled expectation first, as a flat clause.Does the first clause read as something the speaker took for granted? If it is already a surprise, the pattern has nothing to overturn.
2Open the second clause with 哪裡 in front of a knowing verb — 知道, 曉得, 想到.Swap 哪裡 for a real where-question and try to answer with a place. If a place answers it, the slot is still locative, not rhetorical — recast it.
3Land the overturning fact, often carried by 竟然 / 居然, and close on the surprise.Read it back as a denial of knowing, not a request for a location. 'How could I have known' should come out, never 'in which place'.
例 · Examples
1他本來originally, had meant to打算plan to去租影片rent a film，哪裡知道how was he to know (rhetorical: he could not have known)那間店在三天前竟然unexpectedly, of all things關了(had) closed down！
He had meant to go rent a film — how was he to know the shop had, of all things, closed down three days before!
Place-哪裡 wants a location back (郵局在哪裡 → 在台北). Rhetorical 哪裡 takes no place answer; it sits before a knowing verb and denies the knowing. The verb behind it is the tell: a verb of knowing → rhetorical; a verb of being/going → place.
雖然…但是… concedes a known fact and turns from it; the speaker saw both sides. 哪裡知道 claims no vantage to see the turn at all — the surprise was unknowable, not merely conceded.
哪裡知道那間店在哪裡？ → 哪裡知道那間店竟然關了！ (the rhetorical opener denies knowing a fact; it does not ask for a place)
他打算去租影片，但是那間店關了。 → 他打算去租影片，哪裡知道那間店竟然關了！ (但是 only contrasts; 哪裡知道 carries the could-not-have-known surprise)
哪裡他知道店關了？ → 哪裡知道店關了？ (哪裡 sits directly before the knowing verb, not before the subject)
English rhetorical "how was I to know" front-loads "how"; learners reach for 怎麼 or a literal 在哪裡. The fixed opener is 哪裡 directly on the knowing verb, with the where-meaning drained out.