Past Perfect

https://1drv.ms/p/c/5003016f3da1c616/ESIKPlNsVLhDsDSCe-YKK50BDYDc8Yka8wXjVfNncrXv0g 

Explanation 

https://en.islcollective.com/english-esl-powerpoints/grammar-topic/past-perfect-simple-or-continuous-tense/past-perfect/57831