Vatican website translation:
101. 1. In accordance with the centuries-old tradition of the Latin rite, the Latin language is to be retained by clerics in the divine office. But in individual cases the ordinary has the power of granting the use of a vernacular translation to those clerics for whom the use of Latin constitutes a grave obstacle to their praying the office properly. The vernacular version, however, must be one that is drawn up according to the provision of Art. 36.
2. The competent superior has the power to grant the use of the vernacular in the celebration of the divine office, even in choir, to nuns and to members of institutes dedicated to acquiring perfection, both men who are not clerics and women. The version, however, must be one that is approved.
3. Any cleric bound to the divine office fulfills his obligation if he prays the office in the vernacular together with a group of the faithful or with those mentioned in 52 above provided that the text of the translation is approved.
101. §1) Iuxta saecularem traditionem ritus latini, in Officio divino lingua latina clericis servanda est, facta tamen Ordinario potestate usum versionis vernaculae ad normam art. 36 confectae concedendi, singulis pro casibus, iis clericis, quibus usus linguae latinae grave impedimentum est quominus Officium debite persolvant.
§2) Monialibus, necnon sodalibus, sive viris non clericis sive mulieribus, Institutorum statuum perfectionis, in Officio divino, etiam in choro celebrando, concedi potest a Superiore competente ut lingua vernacula utantur, dummodo versio approbata sit.
§3) Quivis clericus Officio divino adstrictus, si Officium divinum una cum coetu fidelium, vel cum iis qui sub § 2 recensentur, lingua vernacula celebrat, suae obligationi satisfacit, dummodo textus versionis sit approbatus.
Slavishly literal translation:
101. §1) According to the age-old tradition of the Latin rite, the Latin language is to be preserved by clerics in the Divine Office, but the use of a vernacular version, created according to the norm of art. 36, is conceded to the power established for the Ordinary, in individual cases, to those clerics for whom the use of the Latin language is a grave impediment at least insofar as they could pray the Office worthily.
§ 2) It can be conceded to the competent Superior, for nuns as well as for [members of] sodalities of Institutes of states of perfection, whether for men who are not clerics or for women, that they may use the vernacular language, even for celebrating in choir, presuming that the version [employed] would be one approved.
§ 3) Any cleric bound to the [recitation of the] Divine Office, if he celebrates the Divine Office in a vernacular language, one with a gathering of the faithful or with those listed under § 2), satisfies his obligation, as long as the text of the version is approved.
The Council Fathers conclude their treatment of the Liturgy of the Hours by considering the language(s) in which it will be prayed. As in other cases in the Constitution, they express a concern that in the Latin rite, the Latin language be retained for public prayer. Nevertheless they recognize that the continued use of Latin may make it practically impossible for some of the baptized to celebrate the Liturgy of the Hours “fully, consciously, and actively.” First among this group would be clerics who, although trained in Latin through seminary formation, may still not find themselves at ease when praying in this tongue. Their local Ordinary can grant permission for clerics in this situation to pray the Divine Office in the vernacular regularly. Second a religious superior can likewise grant that the Liturgy of Hours be celebrated in the vernacular by men and/or women religious in a given community, as long as the translation used has been approved (by the appropriate territorial bishops conference and given recognitio by the appropriate curial congregation). Finally clerics bound to the recitation of the Liturgy of the Hours may fulfill their duty by praying with other groupings of the faithful, even if they use a vernacular version of the texts.
Since Sacrosanctum Concilium was promulgated, the vast majority of clerics obligated to the recitation of the Divine Office do so in the vernacular, although some clerics will recite it in Latin. There are some monastic foundations and religious communities who have preserved celebrating the Liturgy of the Hours in Latin; one thinks of the Benedictine foundation in Norcia with Fr. Cassian Folsom, OSB, serving as prior or the monks at Solesmes. Nevertheless the vast majority of monastic and religious communities likewise have opted for celebration in the vernacular. The same is true of those groups of laity who celebrate the Divine Office in parishes or under retreat center auspices. Pray, Tell readers might want to discuss the benefits and drawbacks of vernacular celebration of the Liturgy of the Hours.