Andreas Schleicher presents at the launch of What does child empowerment mean...
C_16.pptx
1. Endings: Pluperfect Active Subjunctive
Just take the perfect active infinitive and add the personal endings.
Lengthen the ~e~ in ~isse~ in all except the 1st person singular and
the 3rd person.
Add these to the perfect stem. all classes
1st
Person
Singular (I) ~issem
Plural (we) ~issēmus
2nd
Person
Singular (you) ~issēs
Plural (you all) ~issētis
3rd
Person
Singular (he|she|it)
~isset
Plural (they) ~issent