kalimat active/passive past,perfect,past future,past perfect continous

past perfect

• They had used poison gas in World War I.(active)
• Poison gas had been used in World War I.(passive)

past future 

• We thought Dany was going to buy a new car.(active)
• We thought a new car was going to be bought by Dany.(passive)

past perfect continous

• what had Andy been doing (active)
• what had been being done by Andy(passive)