Past perfect text

3.- Voz pasiva: he wites a book = a book is written

he is Writing a book = a book is being written

he wrote a Book = a book was written

he was Writing a book = a book was being written 

he has Written a book = a book has been written

he had Written a book = a book had been written 

he will Write a book = a book will be written 

4.  First conditional: if + present simple en la condicion + futuro simple en el resultado.

 Second conditional: if + past simple en la condicion + would con el verbo en la forma base en el resultado.

 tercer condicional: if + past perfect simple + would have + participio en el resultado.