The pluperfect tense in Latin is formed in 3 steps: 1) Find the perfect stem by removing the "-i" from the 3rd principal verb part. 2) Add "era" to the perfect stem. 3) Add the personal endings used in the imperfect tense. The pluperfect is always translated to English using the word "had", such as "amaveram" meaning "I had loved". Even irregular verbs like "sum" and "possum" follow this formation pattern to create their pluperfect forms.