PAST PERFECT EXERCISES

 https://www.ego4u.com/en/cram-up/grammar/past-perfect-simple/exercises

https://agendaweb.org/verbs/past_perfect-exercises.html

 PAST PERFECT & SIMPLE PAST

 https://www.englisch-hilfen.de/en/exercises/tenses/past_perfect_simple_past.htm

https://www.english-4u.de/en/tenses-exercises/past-simple-past-perfect.htm

https://www.english-grammar.at/online_exercises/tenses/t057-past-past-perfect.htm

https://www.perfect-english-grammar.com/past-perfect-exercise-3.html