同义短语是on purpose,例sb如:
1.Was it an accident or did David do it on purpose?是意外还是戴维故意所为?
2.There were moments when I wondered: did she do this on purpose, was it all just a game, an act?有时我很困惑:她这么做是故意的吗?难道一切都只是一场游戏,是g同逢场作戏?
3.I was deliberately trying to annoy him.; I got him angry on purpose.我故意气他一下。