Hi,
"whose" is used as a subject in Special Interrogative Question? For example:
Whose can do it?
Is the sentence correct? Yes, but here are a few comments.
Consider this example of a correct sentence. 'Whose computer can do it?'
I can omit 'computer' in a context where I have already established the subject, ie that we are talking about computers.
eg (I'm talking to my friends). I need to open this Excel file and my computer won't let me. Whose can do it?
Since you are interested in questions, please note that your first question in this thread is not correct. You need to ask
Is "whose" used as a subject in a Special Interrogative Question?
In addition, in most contexts it would seem redundant to speak of an 'interrogative question'. Why not just speak here of 'a special question'?
Best wishes, Clive