Po pytaniach typu "what", "who" itp. nie daje się operatora, jeżeli pytamy o coś, co w odpowiedzi będzie podmiotem. Czyli:
What makes you cry? -> HE makes me cry. ("he" to podmiot)
ale
What does he do? -> He does SOMETHING. ("something" to nie podmiot)
Tak samo z "what happened?".
What happened? -> IT happened.
Napiszemy "what did happen" tylko w takim przypadku:
- What happened?
- A bomb exploded.
- No, it didn't happen.
- So what DID happen?