The wh- questions in sign languages crosslinguistically can be seen in clause-initial or clause-final position or in both positions. They can be seen in one of the positions in question sentence, like in the example from Austrian Sign Language (ÖGS):
wo ball where ball
Where is the ball?
(Schalber, 2006, p. 142)
Schalber (2006) has pointed in her paper that clause-initial is the default position for the wh- signs in ÖGS. However, the wh-signs can be seen in both positions at the same time. This means that they can be doubled, as in the example below:
was will kaufen was what want buy what
What do you want to buy?
(Schalber, 2006, p. 143)
She has not mention whether there is a condition or not in which doubled questions has occured. So, my question is whether doubled questions are abtirary. Is there a condition in which they have occured?