We shall take two examples to understand better what Active Voice is and what Passive Voice is.
- My brother explained the chapter.
- The chapter was explained by my brother.
Here, both the sentences say the same thing but in different ways. First sentence says what brother did and second sentence says what was done to the chapter.
In sentence 1, explained is the verb, brother is its subject and chapter is the object of the verb explained. In this sentence, subject is the doer of the action that is, subject acts as a performer of the action.
In sentence 2, subject is not the performer because it did not do anything but was done to the subject. So when the subject of the verb is a performer of the action denoted by the verb, that sentence is called to be in the Active Voice.
And when the subject does not perform the action denoted by the verb but is acted upon, that sentence is called to be in the Passive Voice.
In above both sentences, the verbs are of different forms of the same verb: explained, was explained. So the form of a verb used in the sentence tells us its voice whether it is Active or Passive.
You will have more examples on Active and Passive Voice as well as explanation of another Grammar lessons in the website thebestuknow.com which will be easy to understand and go through any exam having questions on English Grammar.