iskazivati

1. (of feelings, attitude) to express; to show
   Ljudi mu stalno iskazuju poštovanje i zahvalnost. — People keep showing him respect and gratitude.
   On ne ume da iskazuje svoja osećanja. — He doesn't know how to express his feelings.
2. formal (of data, documents) to state; to report; to show
   Firma već treću godinu iskazuje gubitak. — The company has been reporting a loss for the third year.
3. (iskazivati se) to prove oneself; to stand out
   Mladi igrač se iskazuje na svakoj utakmici. — The young player stands out in every match.

The perfective is iskazati; in the sense 'to stand out' it takes se.