O, bildiğim kadarıyla, güvenilir bir arkadaştır.
- He is, so far as I know, a reliable friend.
Bildiğim kadarıyla, o iyi bir adam.
- He is, so far as I know, a good guy.
insofar as (or that), to the extent that, to such an extent.
I know he suffered from depression, but surely he wouldn't go so far as to kill himself?.