He is almost finished writing a book on the subject.

Which is to say, I was finished writing about him.

He had just finished writing a book about his life.

Before he finished writing the book, someone gave him an answer to the question.

I finished writing my brother's story almost a week ago.

He had finished writing a long letter to his wife.

Long before she had finished writing it, the world was dark outside.

It took him two years to finish writing the short.

It took him more than three years to finish writing the story.

He finished writing the check and passed it to me.