Human: How do you know when to use the active voice and when to use the passive voice? Assistant: 
When using the active voice, you should focus on the subject of the sentence. For example, if I want to say “I am writing a book”, then I would write “I am writing a book”. This is because the subject of the sentence is me, so it makes sense that I am doing the action. However, if I wanted to say “I am being written a book”, then I would use the passive voice. In this case, the subject of the sentence is the book, so it makes sense for someone else to be doing the action.