Ini idiom kayanya
isn't this better as something like 'saya bos' or something?
That's "I'm the boss," so it has a different meaning because a person can be in charge but not be the boss.
Kalau saya yang berwenang???
This translation means " I am responsible" ? Not necessarily the same as in charge. Maybe there is no word in indonesian that is a better match?
Why not 'I am responsible'?