とはTo think that...!; I cannot believe...
とは presents a fact as surprising, shocking, admirable, or difficult to believe. It often corresponds to “to think that...!” or “I can’t believe...” in English.
Reacting to a remarkable fact
The clause before とは states the fact that prompts the reaction. The reaction may be disbelief, shock, admiration, or pleasant surprise; this pattern is not inherently negative.
An explicit reaction
彼が独学であれほど高度な技術を身につけたとは思わなかった。
I never imagined that he had acquired such advanced skills on his own.
Analyze思わなかった makes the speaker’s surprised reaction explicit.
Stopping at the reaction point
When the sentence ends with とは, the listener supplies an unstated reaction such as “I can’t believe it” or “what a surprise.” Tone and context carry much of the effect.
A dramatic sentence ending
信頼していた部下が資料を改ざんしていたとは。
I can’t believe the subordinate I trusted had falsified the documents.
AnalyzeThe shock is left unstated after とは.
Positive surprise and disbelief
The following reactions show that the construction can express admiration as well as disbelief.
Reaction or definition?
The same written form can introduce a formal definition. Look at what follows: surprised とは reacts emotionally to the fact stated by a clause, while definitional とは takes a term and explains what it means.
More examples
あの若さで三つの会社を経営しているとは、たいしたものだ。
Running three companies at such a young age—that is remarkable.
Analyzeいつも慎重な彼が、確認もせずに契約書へ署名するとは。
To think that he, normally so cautious, would sign the contract without even checking it.
Analyze失われたと思われていた原稿が百年ぶりに見つかるとは、夢にも思わなかった。
I never dreamed that the manuscript thought lost would be found after a century.
Analyzeこの静かな青年が、舞台ではあれほど大胆だとは驚いた。
I was amazed that this quiet young man was so bold on stage.
Analyze彼が約束を破るとは、どうしても信じられない。
I simply cannot believe that he would break his promise.
Analyze