Read the following sentences:

Active: Do the children play football?
Passive: Is football played by the children? (NOT Do football played by the children?)
Active: Did Alice invite you?
Passive: Were you invited by Alice? (NOT Did you invited by Alice?)

Note:

As you may have noticed, the auxiliaries do, does and did are not used in the passive.

Active: Have you finished the work?
Passive: Has the work been finished by you?

Notes: The auxiliaries has, have and had are used in the passive, but they change their form according to the number and person of the passive subject.

Active: Can anyone cure it?
Passive: Can it be cured?
Active: Will he accept our invitation?
Passive: Will our invitation be accepted by him?

Note:

The auxiliaries can, may, will and shall do not change their beginning position when active voice is changed into the passive voice.

Active: Whom did you laugh at?
Passive: Who was laughed at by you?

Active: Who killed the snake?
Passive: By whom was the snake killed?

Note:

Who changes to by whom in the passive; (by) whom changes to who in the passive.

Active: Why did he punish you?
Passive: Why were you punished by him?

Notes:
The question words when, where, why, how and what do not change their beginning position when the sentence is changed from the active to the passive.