As mentioned earlier, grammarian Martha Kolln mentions agency as one of the most important aspects of verb you should know about. Agency involves understanding the relationship between the subject and the verb in a sentence and whether or not the subject is the agent in the sentence.
Take a moment to read the following two sentences.
The zombie survival guide was grabbed by Amy.
Can you see how these sentences are different?
In the first sentence, the verb grabbed is active because its subject, Amy is the doer or agent. Amy did the grabbing.
In the second sentence, was grabbed is passive because it describes an action done to its subject, guide. The doer of the action, Amy, is now the object of the preposition by.
We want to use active verbs whenever possible as they allow us to express ourselves clearly, succinctly, and strongly. Active verbs imply that we’re confident with what we’re saying; we believe in our words. Looking back at the two sentences, we can see that the first one uses fewer words and makes no mistake as to who did the action. The latter sentence is wordy and does not directly address Amy.