What about: "ontmoet je hem vaker?" ?
vaker = more often
but i guess that dutch people use it by each other, Right??
No, it's a superlative for a reason.
i meant that it does not matter if we use "vaak" or "vaker".
It does, it changes the meaning of the sentence, as explained..
Why not "ontmoet je vaak hem"?
That's an incorrect word order, hem (a personal pronoun that is the direct object) comes before vaak (time).