Who saw him? (subject) vs Who did he see? (object)
Subject Q: Wh-word + verb. Object Q: Wh-word + auxiliary + subject + verb
Subject Q: Who didn't come? Object Q: Who didn't you invite?
These ARE questions
💡 Subject questions look like statements with wh-word. Object questions have normal question structure.
✓Who broke the window? (subject)
✗Who did break the window?
No auxiliary when 'who' is subject.
✓Who did you see? (object)
✗Who you saw?
Auxiliary needed when 'who' is object.
✓What happened? (subject)
✗What did happen?
No auxiliary when 'what' is subject.