ところが

In a sentence

• 彼は勉強をしていましたが、ところが試験には落ちました。

  He was studying, but surprisingly he failed the exam.

  In this sentence, 'ところが' introduces an unexpected turn of events contrary to what was implied earlier.

• 問題に取り組んでいたところが、時間切れになってしまった。

  I was working on the problem, but unfortunately, time ran out.

  Here, 'ところが' indicates an event or situation where expectations were not met due to an obstacle.

• あの映画は面白そうでしたが、ところが退屈でした。

  That movie seemed interesting, but it was boring.

  This use of 'ところが' demonstrates a surprising or contrary result to the initial impression or expectation.