Correva troppo forte perché lo potessimo raggiungere.

[zzcguns]

English Translation

He ran too fast for us to catch up with.

Interesting use of perché.
The combination troppo … perché means “too (much) … for”.

As an example, here are some translations using è troppo forte perché on dictionary.reverso.net
è troppo forte perché translation in English | Italian-English dictionary | Reverso

[zzcguns]

@mike , thanks so much for including the automatically added translation feature.