Translation of "which" into Afrikaans

Which is the most difficult language in the world?

Watter taal is die moeilikste ter wêreld?

Which is the more expensive of the two?

Wat is die duurder een van die twee?

Behold, I have but few things to write, which things I have been commanded by my father.

Kyk, ek het net ‘n paar dinge om te skrywe, welke dinge ek beveel is deur my vader.

You may remember that these men even argued among themselves about which one of them was the greatest.

Jy onthou dalk dat hierdie manne selfs onder mekaar gestry het oor wie van hulle die belangrikste was.