- Active Voice
When sentences are in active voice, the subject of the sentence is doing the action of the sentence.
Sentences in active voice are often less wordy and easier to understand.
The subject of the sentence is Mrs. Turner. She performed the action of the sentence -- teaching the class how to write a poem. This sentence is in active voice.
In this sentence, the subject is class, but the class did not perform the action of teaching in the sentence. That was done by Mrs. Turner. This sentence is not in active voice.
In writing, it is best if most sentences are in active voice.