“The passive voice of “I can write a book on grammar” is:”

"In passive voice “I can write a book on grammar” becomes “A book on grammar is written by me.” The subject (I) becomes the agent and the object (book) becomes the subject with the verb adjusted to “is written.” Passive voice is used in English to emphasize the action or object over the doer common in formal writing or when the agent is less relevant. This structure enhances flexibility in sentence construction aiding clarity in academic or professional communication."