C. In present simple questions, we use do/ does (e.g. Do you live near here?)
a. In past simple questions, we use did. (e.g. Did you sell your car?)
b. But do not use do/ does/ did if who/ what etc. is the subject of the sentence. (e.g. Somebody telephoned Emma. Who telephoned Emma? vs. Emma telephoned somebody. Who did Emma telephone? Who wants something to eat? (not Who does want))
C1. Questions ending in prepositions are very common in English. After Who, Which or What we often have a preposition at the end of the sentence. (e.g. Who does this book belong to?)
a. the position of preposition in questions beginning Who/ What/ Which/ Where …? (e.g. Who do you want to speak to?)
b. We can use preposition + whom in formal style. (e.g. To whom do you wish to speak?)