を見つけることができた

was able to find

→ を
phrase Rare #20,513
was able to find Used to say that someone succeeded in finding something. The present form を見つけることができる means “can find” or “is able to find.”
JA: 長い間探して、やっと鍵を見つけることができた。
EN: After searching for a long time, I was finally able to find my keys.

トム探し物を見つけることができた

Was Tom able to find what he was looking for?

とても時間がかかった私たちはやっとそれを見つけることができた

It took a very long time, but we finally managed to find it.

メアリー探し物を見つけることができた

Was Mary able to find what she was looking for?

トムを見つけることができた

Were you able to find Tom?