Znam and wiem too are the prsesnt tense but where is all this leading to?
'znam' coś/kogoś mean i'm able to recognize sth or sb
'wiem' mean i have some knowledge
So we can say "znam go" and we cannot say " wiem go" because he is not a form of knowledge - he is a person.
Wiem jak (go) rozpoznać/poznać
Wiem jak (on) wygląda - Such expressions are correct