Questions without auxiliary verbsQuestion word AuxiliarySubjectVerbWhodoyoulove?Question word verbobjectWholovesyou? The first question is a normal question and uses the form which we almost always use for a question: question word + auxiliary + subject + verbIn the second question, the question word is the subject. When the question word is the subject there is no auxiliary verb and the verb agrees with the subject.Other examples:Question word verbobjectWho wrote Romeo and Juliet?Whowonthe 2006 World Cup?Which playerfouledRonaldo?Which actorwonthe oscar?Whathappened?It depends upon the function of the question word in the sentence. If for example who/what/how question the subject/agent (not the object) you don't need "do" (old Germanic way):Who came here? (questions the subject)Who did you speak with. (questions the object)This confusion is also partly due to the fact that "who" has taken over the function "whom", the question word for the object, filled when it fell out of use except in very formal writing.What happened? (subject)What did you do? (object)How many people died? (subject)How many people did you interview? (object)In sentences with "have" used in the active (present perfect)/passive:I have repaired the car. Have you repaired the car? (present perfect no do is used)I have the car repaired. Do you have the car repaired? (passive usage with do)