Although common trade languages have been developed, there is no one majority language in Citadel Space.
Most individuals know only their mother tongue, and rely on machine translation. Modern portable computers allow anyone with a few hundred credits of equipment to enjoy seamless real-time translation of alien languages, courtesy of handheld PDAs, computers in clothing or jewelry, or sub-dermal implants. Without fast and accurate translation, galactic trade and culture would not exist.
Governments provide subsidized software, updated through the public extranet "on the fly", often as users approach spaceport customs facilities. Even the batarians, who isolated themselves from galactic society nearly two decades ago, take pains to provide up-to-date glossaries and linguistic rules, though most suspect that this is only so they can continue exporting propaganda.
Then there are speech-to-text translators (commonly abbreviated to "STT"), a class of speech recognition software, used to input and format dictated messages for a variety of applications. Although STTs can be used in conjunction with language translation systems, the "translation" referred to is from spoken to written language. Depending on the language concerned, this may be as simple as automated dictation, or involve complex processes such as reformatting, interpolation, syntax adjustment, and so on
A majority of Thessian-derived cultures employ a technique known as “multilanguage” to achieve an enhanced relation between spoken language and the cultural and emotional connotations of the concepts being expressed. Asari speaking High Thessian - or any of the dozens of other multilanguage structures common in asari space - switch between various vocabularies and syntaxes, often in mid-sentence or even mid-word, in order to augment the literal meanings of their words with additional connotations.
See: Asari Language
As a turian CDN contributor once noted:
"Spirits alive. Your alphabet. I have never seen such a complicated writing system. No wonder you have such long lifespans. It must take a generous fraction of it just to gain a decent sized vocabulary".
Batarian languages are notable for the importance played by bodily posture and other physical cues.
See: Batarian Language
The "batarian language" isn't a single entity, despite the previous government wishing it were. The Hegemony was a collection of nations, and each nation had its own dialect (which pre-galactic contact were seen as separate languages entirely). These have been diluted a lot with international and then interstellar mixing, but they form the core of the "batarian language". Then you have the castes. Each nation has castes - there are even different subcastes in some of them - and each gradually developed its own slang, which followed more or less the same pattern as the batarian language "proper" - mixing and mingling ever more as time went on.
“It’s a mess with a lot of words ripped from other languages in it. This is what happens when you take industrial-age people from all corners of a planet and throw them into modern dome cities”.
Elcor speech is heard by most species as a flat, ponderous monotone. Among themselves, scent, extremely slight body movements, and subvocalized infrasound convey shades of meaning that make a human smile seem as subtle as a fireworks display. As such, spoken language is only one of many contributing channels. Since their subtlety can lead to misunderstandings with other species, the elcor prefix all their dialog with non-elcor with an emotive statement to clarify their tone.
Languages include Thrruum and Ba-Baar.
The hanar communicate using sophisticated patterns of bioluminescence, which other species need machine assistance to translate (though many drell apply genetic modification to their eyes in order to perceive higher frequency flashes which allows them to understand the hanar).
Hanar languages reflect that the hanar sense of the existence of the individual is a lot smaller than in humans or asari. It's not that the individual doesn't exist (indeed, the majority of hanar religious traditions are led by a charismatic individual), it's just that the plurality is given more importance. (Those that rule are aware that they rely on the confidence of the hanar under them, or the hanar will just leave). The one is part of something larger than itself, and language reflects that.
Most hanar speak The Word Of Primacy Supreme (AKA Supreme Primacy), as this is considered the direct evolution of the language of the old Illuminati. Another branch of the Word is Elegant Reflection on White Sand.
Humanity utilises a multitude of languages and dialects, including developing colonial and spacer dialects. The Systems Alliance uses English and Mandarin Chinese as its working languages.
See: Krogan Language
Tuchankan languages and dialects include Old Urdnot, Ghurst-Jorgal (which has not had political significance in 300 years), Krestnock, and New Krestnock.
Now that the quarians are reduced to a small, insular population, they have one common language known as Khelish.
Raloi languages include Ranejha.
Salarian languages include:
- Eredraean (including the South Sievii dialect). Note: a language of Mannovai.
In many salarian languages, inflection rather than grammatical particles communicate structure. Word order is often not very important - they want to get whatever they think is most important said first, then move on to the details.
- Aplis: The primary language on Solregit
- Ark Palaven
- Imperan: The primary language on Macedyn, among others.
- Palaven Standard
- Gruul Trade (See: The Gruul Cluster)
- Omegan Trade (See: Omega)
- Yrn, used on Tortuga.
- Zhulthai, a language of The Rainreaved Ocean, of turian origin.
Yahg mouths are more developed than most and capable of producing sounds other species cannot, which makes translation a difficult matter, and has since first contact. Most commonalities are in words which originate with sounds used in nature; for example, many yahg words for ‘no’ and other negative responses are onomatopoetic sounds of pain or distress. These are recognizable as such by most yahg, whether or not they can otherwise communicate verbally. Yahg languages developed out of natural requirement and rarely contain more than fifty thousand words, one of the reasons why many yahg on Parnack are quickly adopting the languages of other races. Batarian language is proving particularly popular.