てっきり
てっきり
adverb
surely; certainly (mistaken belief)
1.
surely; certainly; definitely
Used when the speaker was confident about something that turned out to be wrong, or when expressing a strong assumption. Often implies the belief was mistaken.
てっきり彼が来ると思っていた。
I was sure he would come.
てっきり日本人だと思ったら、韓国人だった。
I was certain they were Japanese, but they turned out to be Korean.
てっきり知っているものだと思っていた。
I assumed you definitely knew about it.
USAGE PATTERN:
てっきり is almost always used with past tense or assumptions that proved wrong. It expresses that the speaker was confident about something.
COMMON PATTERNS:
- てっきり〜と思う - to be sure that ~
- てっきり〜と思っていた - I was sure that ~
- てっきり〜だと思ったら - I was sure it was ~, but then
NUANCE:
Implies strong confidence that was potentially or actually mistaken. Often appears in sentences where the speaker's assumption turned out to be wrong.
CONTRAST:
- きっと - certainly (neutral, not implying mistake)
- てっきり - certainly (often implies the assumption was wrong)