Direct: (vraagwoord) - persoonsvorm - onderwerp. Always ends with question mark.
Who are you?
Indirect:
Onderwerp - persoonsvorm - vraagwoord - onderwerp - persoonsvorm Does not end with question mark.
I wonder who you are.
werkwoord - vraagwoord - onderwerp - persoonsvorm Always ends with question mark
Could you tell us who you are?
Geen vraagwoord? Dan voeg je 'if' of 'whether' toe. Pay attention to the auxiliar verb!
Did he see that UFO?
I wonder if / whether he saw that UFO.
Can you tell me if / whether he saw that UFO?