To think that…!: 〜とは
plain form (N／な-adj with or without だ) + とは（！／思わなかった／驚いた）
Plain form + とは（！／思わなかった）: “to think that…!”, surprise or indignation at an unexpected fact. More formal than なんて; distinguish it from the definition 〜とは〜のことだ.
In short
〜とは, placed after a fact, expresses surprise or indignation: “to think that…!”, “I never imagined that…”. The speaker discovers something unexpected, and what follows (思わなかった, 驚いた) is often left unsaid. Written and careful spoken register.
- こんな所で先生に会うとは！こんなところでせんせいにあうとは！To think I'd run into my teacher here!
- まさか彼が優勝するとは思わなかった。まさかかれがゆうしょうするとはおもわなかった。I never imagined he'd win.
- 十月なのに、こんなに暑いとは。じゅうがつなのに、こんなにあついとは。To think it's this hot in October…
The basics
You already know 〜とは for defining a word (“X means…”). This is a different use: とは follows a fact that has just happened, and the speaker shows they didn't expect it at all. It's English “to think that…!”, “who'd have thought…”.
The surprise can be joyful, admiring or indignant. The sentence often stops dead after とは: the tone is enough, and the rest (“I couldn't believe it”) is implied.
I never imagined he'd win.
- other
- noun
- verb
- particle
- あの小さな町工場の部品が、宇宙に行くとは！あのちいさなまちこうばのぶひんが、うちゅうにいくとは！To think that parts from that little workshop are going into space!
How to form it
とは goes after a plain form (present, past, negative). With a noun or a な-adjective, だ is optional: both 学生だとは and 学生とは are possible. The typical follow-up: 思わなかった, 思ってもみなかった, 驚いた, 信じられない, あきれた.
| Before | Example | Common follow-up |
|---|---|---|
| Verb | 彼が来るとは | 思わなかった |
| Past verb | もう終わったとは | 驚いた |
| い-adj | こんなに高いとは | 知らなかった |
| な-adj / Noun | まだ学生（だ）とは | 信じられない |
- この料理がこんなに高いとは知らなかった。このりょうりがこんなにたかいとはしらなかった。I didn't know this dish was so expensive.
- あの人がまだ学生だとは、信じられない。あのひとがまだがくせいだとは、しんじられない。I can't believe he's still a student.
Surprise or definition? Look at the position
The definition (seen at N3) puts とは right after a word, at the start of the sentence, and ends with 〜のことだ or 〜という意味だ. The surprise puts とは after a whole clause, with a verb or an adjective, and ends with a reaction (or nothing).
| Sentence | Use |
|---|---|
| 「物価」とは、物の値段のことだ | definition (N3) |
| 物の値段がこんなに上がるとは！ | surprise (N2) |
- 「リニア」とは、磁石の力で走る電車のことだ。「りにあ」とは、じしゃくのちからではしるでんしゃのことだ。The “rinia” (maglev) is a train that runs on the power of magnets.
- 名古屋から東京まで四十分で行けるとは！なごやからとうきょうまでよんじゅっぷんでいけるとは！To think you'll be able to get from Nagoya to Tokyo in forty minutes!
Compare with なんて
なんて (N3) also expresses surprise, but it's more spoken, more emotional, and often a bit scornful (“something like that…”). とは is more composed and more written: you find it in articles, speeches, novels, and from people who speak carefully.
- こんなミスをするなんて、ばかみたい。こんなみすをするなんて、ばかみたい。Making a mistake like that — how stupid. (spoken, casual)
- これほどのミスが起きるとは、だれも予想していなかった。これほどのみすがおきるとは、だれもよそうしていなかった。Nobody had foreseen that a mistake on such a scale would happen.
Common mistakes
- Reading every とは as a definition: after a verb or a whole clause, it's almost always surprise.
- Missing the emotion when the sentence stops at とは: “彼が来るとは。” really means “to think he's coming!”.
- Using it for something predictable: とは assumes a real gap with what you expected.
7 exercises on this point
Particles to choose, sentences to put back in order, translations: marked straight away, then reviewed at the right time. This JLPT N2 point is on the Aonami Line (Science and technology) of the Nagoya lines.