In my GOAA suburban parish, the priest's parts are probably 90% in English on Sunday's; the choir, about 60% (our wacky, but dedicated choir director doesn't think "Kyrie Elieson" should ever be rendered into English). Weekdays/evenings, tend to be more Greek, our priest truly uses the "flexible bilingualism" practice; serve in the language those attending seem most comfortable with. Applying the same practice, the Sacraments of Holy Matrimony and Christenings are performed mostly in English. At Pascha, he will proclaim "Christ Is Risen," in Greek, English, and Church Slavonic. When our bishop visits, he has "Lord Have Mercy," during the petitions of the Blessing of the Five Loaves (Artoclasia), chanted in Greek, English, Church Slavonic, Romanian, and Arabic.