Fill in the blank with the correct form of tense: Justin _________ a book…

Correct answer: Justin is writing a book about his adventures in Tibet.

Why this is correct:

• Present continuous (is writing) describes an action that is in progress now or a temporary project happening around the present time.

• The clause 'I hope he can find a good publisher when he is finished' implies the book is not yet finished, so a tense that shows ongoing activity is required.

• Present perfect (has written) would mean the book is already completed, which contradicts the idea that he will be finished in the future.

• Simple present (writes) is used for habits or general facts, not for describing a specific ongoing project.

• Simple past (wrote) indicates a finished action in the past and does not match the context.

Correct sentence: Justin is writing a book about his adventures in Tibet. I hope he can find a good publisher when he is finished.