I came across this following sentence as I was making a practice about grammar. " Who got up first this morning?" I didn't understand why they used "got up" intead of "did get up". Can someone explain?
Subject-auxiliary inversion does not apply to questions headed by an interrogative pronoun representing the subject of the question, so there is no need for the dummy auxiliary do.
Whom did you get up? ... Here the interrogative pronoun Whom represents the object of get, so did is inserted to accomplish inversion with the subject, you.
Who got up? ... Here the interrogative pronoun Who represents the subject of get, so inversion is not required, and do is not inserted to accomplish it.