Working on the book: Raymond Murphy. "English Grammar in Use - Fifth Edition" (p. 109)
Chapter 49: Questions 1
But do not use do/does/did if who/what etc. is the subject of the sentence. Compare:
Some of the exercises at the end of the chapter are giving me troubles:
49.2 Make questions with who or what.
4a. I'm worried about something.
12a. Sarah was with somebody.
4b. What are you worried about ?
12b. Who was Sarah with ?
In ex. 4, what is the object. And, in ex. 12, who is also the object. So, according to the book, do/does/did should be used.
I'll appreciate if someone could explain what's happening, here.