Judoonese, sometimes just called Judoon, was the language of the Judoon. (AUDIO: Judoon in Chains, COMIC: Gangland) The Sixth Doctor once told Captain Kybo that English was much more expressive than Judoonese. Kybo agreed, noting in particular that Judoonese had "nothing to compare" with poetry. (AUDIO: Judoon in Chains)
Nevertheless, Judonese was a language built on rhyme. It was comprised of words ending in a vowel -- generally an "o" sound, but occasionally an "a". (TV: Smith and Jones; PROSE: Judgement of the Judoon) Each sentence was composed of several of these words strung together. (TV: Smith and Jones) The Sixth Doctor called the language "uninflected" and "monosyllabic", while noting that it was "rather too basic" for the TARDIS translation circuit to work on. (AUDIO: Judoon in Chains) The TARDIS' "blind spot" for Judoon was the reason that the Doctor had to speak Judoonese unassisted on occasion. (TV: The Stolen Earth; AUDIO: Judoon in Chains)