Anno Domini, Ad Infinitum, and Aqua Pura: Translating Latin Phrases to English as a Grammatical Exercise

One of the most influential languages, Latin continues to bombard our daily lives in the many Latin phrases we take for granted. Using these phrases as models for proper Latin grammar, the Latin student can focus his/her attention on the structure of Latin without the complication of translating long, cumbersome sentences from Latin to English.

Anno Domini, sometimes abbreviated AD or A.D., is a Latin phrase used to indicate dates of the Julian and Gregorian calendars. This designation is indicative of the time after the birth of Jesus Christ in contrast to dates before His birth which are designated with BC or B.C..

Anno Domini can be literally translated as “in the year of the Lord” but is often mistranslated as “in the year of our Lord.” “Anno” is an excellent example of the use of the “ablative of time when or within which.” This construction is used to indicate when something takes place. Unlike other ablative constructions (but similar to the ablative of means or instrument) the ablative of time when does not use a preposition such as “in”, “at”, or “within.” These words must be appropriately supplied when translating from Latin to English. A literal translation of “Anno” in this case can be “in the year.”

“Domini” is simply the genitive form of the word “Dominus” and is used in this case to indicate possession, or to whom the year (Anno) belongs. Recall that the genitive is often used to indicate possession. Therefore, “Anno Domini” may be properly translated as “in the year of the Lord.”

Ad Infinitum is a phrase that literally translates as “to infinity” but is colloquially translated to mean “forever”, “ongoing”, or sometimes even “to the horizon” (a metaphor for "forever"). Ad Infinitum is an excellent example of the use of the accusative of place to which. This construction is formed with a preposition plus the accusative case making it easier to recognize than constructions that do not use a preposition.

“Ad” is a Latin word which may be translated as “to” in contrast to “ab” (or just “a” when followed by a consonant) which means “from.” “Infinitum” is the accusative form of the word “infinitus” meaning “infinite”, “unbounded”, or “endless.” Do not confuse this form of the word with the neuter form, which is also “infinitum” in both the nominative and accusative cases. Together “ad” and “Infinitum” may be translated as “to infinity.” Notice that the accusative of place to which need not refer to any particular place but can be used to indicate a theoretical place or destination such as infinity.