This is the 8501st most frequent Polish word.
potrafił
"Potrafił" means "he was able to" or "he managed to."
'Potrafił' is used here to indicate the ability to accomplish a specific task in the past.
On potrafił naprawić samochód bez żadnej pomocy.
He was able to repair the car without any help.
'Potrafił' expresses a general skill or capability that someone had during a specific period in the past.
Kiedy był młody, potrafił biegać bardzo szybko.
When he was young, he could run very fast.
'Potrafił' is negated here ('nie potrafił') to indicate the lack of ability in the past.