かと思うと / -かと思ったら

Usage

Used to express the fact that a matter is changing to a next matter in a short time

Vた + かと思うと

娘が帰って来たかと思うと、すぐに家を出ていった Just as my daughter returned home, she was out the door again

うちの近くの公園の花が咲いたかと思ったら、もう散ってしまった No sooner than the flowers were starting to bloom at our nearby park, the pedals had fallen