At a glance
～かと思いきや means "I thought ~, but (actually) ~". It is used when the real result turns out to be the opposite of what the speaker expected.
Verb / い-adj (plain form) + かと思いきや、[unexpected result]
Noun / な-adj stem + かと思いきや、[unexpected result]
雨が降るかと思いきや、いい天気になった。 I thought it would rain, but it turned out to be nice weather.
How to form it
かと思いきや attaches to the plain form of the expectation. With nouns and な-adjectives, だ is dropped before か.
| Attaches to | Form | Example |
|---|---|---|
| Verb | plain form + かと思いきや | 降るかと思いきや / 終わったかと思いきや |
| い-adjective | plain form + かと思いきや | 難しいかと思いきや |
| な-adjective | stem (no だ) + かと思いきや | 静かかと思いきや |
| Noun | noun (no だ) + かと思いきや | 中止かと思いきや |
思いきや itself does not conjugate. Politeness is shown at the end of the second clause: ～かと思いきや、簡単でした。