An illustration shows you exactly what the book is trying to portray by using pictures or descriptive text. An illusion can be used to deceive someone or something into making it look like it is something else.
The pronoun in the sentence is the word: Someone. The type of pronoun in the following sentence is an example of an indefinite pronoun. An indefinite pronoun is a type of pronoun that does not particularly indicate a person, thing or amount.
Answer:
he was considered a genius by marry
the stairway must have been placed by the trespasser
the car was given to me by my mate
