The basic structure of the Mass is largely unchanged since the 6th cent. In the Counter Reformation the forms were restricted and local variants eliminated. As a result of the Constitution on the Sacred Liturgy of the Second Vatican Council, the Roman Mass liturgy has undergone extensive reformation. The revisions include the use of the vernacular languages in the place of Latin, an emphasis on congregational singing, latitude for modifications that may be introduced by local bishops, additional eucharistic prayers, and communion in both bread and wine. In 2011, however, a new English translation of the Mass was put into effect. The changes were designed to align the English text more literally with the Latin, and revised much of the wording adopted after Vatican II.