Translation software

Translation software is computer software designed to help translate information from a foreign language into the native language of the person viewing or hearing the information.

Covenant
Despite having their own native languages, the races of the Covenant appear to use the Sangheili language as a lingua franca for interspecies interaction. However, some races, such as the Huragok and Yanme'e, have difficulty speaking another languages. To better interact with the Yanme'e, signal units contain translation software which translate another language into the Yanme'e language. While Huragok usually communicate with other races by a sign language, Covenant ships also possess extensive lexicons which can give Huragok orders.

Forerunner
The Forerunners possessed extremely robust translation software in their computers. When John-117 accessed the Terminals in the Ark, the computer was able to use words and measurements native to humanity for approximate translations. The San 'Shyuum managed to access a number of files within the Dreadnought thanks to those systems, but they misinterpreted a number of glyphs, coming to believe that the Halo Array was used to "transcend life", instead of wipe out life.

UNSC
Early into the war with the Covenant, the United Nations Space Command developed software to help translate the languages the alien races of the Covenant spoke, such as the TSV-442, which assisted in early interrogations of Covenant prisoners. However, while the UNSC was able to make a literal translation for Covenant words, the true meaning behind them could often be extremely disjointed. This was solved when the A.I. Cortana managed to access a Covenant lexicon aboard the Ascendant Justice, making a more accurate English-Covenant lexicon. It would seem that it was around this time that the Sangheili language was deciphered, as translation software in the weeks preceding and succeeding the events of Operation: FIRST STRIKE was heavily updated.