English

English is a West Germanic language originating in England and the first language for most people in Australia, Canada (French also being a main language in that country), the Commonwealth Caribbean, Ireland, New Zealand, the United Kingdom and the United States of America (together, commonly known as the Anglosphere). This language has grown to prominence as the dominant language of the UNSC and the human species, and is the primary language of every known UNSC colony and organization.

Several other languages are used throughout the UNSC, mostly with secondary roles in society, as English is always found in conjuncture with them. Such languages include Swahili, Hungarian and Spanish.

Covenant translation software cleverly intercepted human COM transmissions after the First Battle of Harvest, and thus the Covenant learned English quickly. From 2525 to 2552, the Covenant used this knowledge mainly to broadcast florid curses at human colonies and ships before destroying them, and never actually held conversation with humans.

UNSC translation software has been able to decrypt a number of Covenant languages, most notably those of the Unggoy, Sangheili, and San 'Shyuum. By the time of the Battle of Earth, this software could automatically interpret everything the other races said, and has apparently been installed in the equipment of all UNSC military personnel, as all personnel appear to have the ability to understand what members of these races are saying. This is the reason that Grunts, Elites, Brutes, and Prophets heard in Halo 2 and Halo 3 seem to be speaking English. Additionally, some of the members of the Covenant, mainly Sangheili and Unggoy, actually know how to speak English.