• てっきり雨だと思っていたら晴れた
    • I was sure it was going to rain, but it turned out to be a fine day.
    • どろぼうはてっきり逃げたと思ったら屋上に隠れていた
    • We were convinced that the thief had got(ten) away, but he was hiding on the roof.
    • てっきり電話をくださると思っていました
    • I took it for granted that you would phone me.