Question

who is knocking at the door.(change the voice)

Answer 1

Answer:

By whom the door is being knocked.

Answer 2

Explanation:

Verb in any sentence are used either in active or passive voice.In the active voice,the subject is a doer of the action while in passive voice,the subject of the sentence is not the doer but action itself.The object in the active voice becomes the subject in the passive voice.

Active voice:-

A verb is said to be in the active voice when the subject acts or performs the action.

Rule:-

Sub+Verb+Object

Passive voice:-

A verb is said to ve in the passive voice when the subject of the verb is passive and receives the action done upon it

Rule:-

Sub+auxiliary verb,+V third form+by+object

Ans:-

The door was knocked by whom?