Letters that make past perfect tense
s, a, e, f, n, p, c, r, t are letters that make 'past perfect tense'
Words within past perfect tense
ER, PA, RF, pe, te, EC, Pa, en, perfect tense, SE, past perfect, perfect, past, ten, tense, as, pas, ECT, CT, AS, pa, As, Er, Fe, Rf, Se, Te are words within 'past perfect tense'