During the different franchise series (excluding ENT) there are only very few encounters with new or unknown species the crews of the ships don't understand. Most often even the most alien species utilizing recognizable speech seem to speak English (or whatever dubbing you're watching).

There have been explanations on why the Universal Translator sometimes seem to skip words or whole sentences.

In short it somehow picks up brain waves and the like and uses them to translate by intention/supposed context.

But how about Voyager traveling through Delta quadrant, which hasn't been explored yet? It's a first contact situation almost every single time. Yet the universal translator seems to pick up their language instantly, even on real first contacts, greetings, etc. The translator probably isn't able to scan brain waves etc. when other, more important systems (like target scanners, sensors, etc.) can't get through shields either.

Also I'm afraid it still doesn't explain situations when some of the crewmen are outside without any scanning gadgets on them. Sometimes even without their com badges.

  • My guess as to why the translator doesn't "always" translate the full dialog of say "famous nasty Klingons" is possibly because they begin speaking in English, and throw in some Klingon phrases. So the translator thinks they're talking in English anyway, and doesn't attempt to translate what otherwise may be a sneeze. Jul 7, 2014 at 21:19
  • If you feel this question isn't a duplicate of the one Richard linked, please make an edit to clarify how the answers you're looking for should be different from good answers to that question.
    – BESW
    Jul 7, 2014 at 21:27
  • thanks, i've just edited the question but maybe it's still not enough
    – daremes
    Jul 7, 2014 at 21:45
  • 2
    As to the "Why does it work instantly?": I guess to avoid repetitions and "boring" learning time. Look at Stargate SG1. The first few episodes started with language barriers, but they dropped those pretty fast. The only scifi-series I know that got language barriers right (and not boring) is Babylon 5: The viewers understand spoken language on a point-of-view basis, i.e. if you follow character x, who doesn't understand, the viewers don't either (actually similar to the companions in Doctor Who).
    – Mario
    Jul 8, 2014 at 8:19
  • 2
    As for how new ships can speak upon meeting, I had always assumed that most space faring races, would have some kind of primer key sent during communications (mathematical code), so that the computers could first sync the signal, then use it as a basis for translation, similar to the gold plate we sent off on voyager, explaining how we speak and what we hear.
    – Ordeiberon
    Jul 9, 2014 at 15:00

4 Answers 4


[This paragraph is all TVTropes links] So, put simply and out-of-universe-ly, this is just a kind of Applied Phlebotinum called Translator Microbes (from Farscape), which is also known as Universal Translator (link redirects to Translator Microbes). The name should give a clue: It's one of few common ways of dealing with alien languages, given solely for the benefit of the viewer, and it permeates both shows.

That said, for in-universe, Star Trek has changed the explanation over the years. The first explanation, from The Original Series, was the brainwave-scanning one you mention in the question. ThinkingStiff shows quite a few issues with that explanation here.

The other explanation is that most languages follow one of several grammatical patterns, which make it easy for the universal translator to match it to one of them. Or if there are issues, to modify one of those patterns over time and come up with a new translation matrix that works for that new language. (No, this does not explain specific nouns/etc when it comes to new languages)

There are two instances of this failing that immediately come to mind:

  • The infamous Darmok episode of TNG, where the Universal Translator was working perfectly but didn't have the context for a semantic translation. Their language was made up entirely of memes specific to their culture, so while we could hear the translation of each word or sentence, we didn't know what they were referencing, so the meaning didn't come across.
  • The Skrreean language from DS9 was another different enough that the Universal Translator had difficulties with, but over time it was able to adjust and learn that language as well.

I can't find it at the moment, but there was an explanation in one of the ENT episodes (I believe during Season 1), where Hoshi Sato explains that most languages, alien or otherwise, are based on a limited number of patterns, which the translator is able to use as a baseline to establish a translation for. The UT's failure with some languages would simply mean that they fall outside one of these common patterns.

Now, as for why these patterns even exist? 4.5 billion years ago, the ancient humanoids seeded life across this part of the galaxy:

Believing that the life span of a single species was finite, the ancient humanoids seeded the primordial environments of many planets with a DNA code that would direct the evolution of life on that planet towards a form similar to their own.

And additionally, Sargon claimed that his people did the same thing, around 600,000 years ago.

The universal translator worked on both of these species, implying that their seeding life did not just push physical form, but also affected mental processes, causing a limited number of language patterns to form in humanoids.

While the ancient humanoids only seeded our area of the galaxy, Sargon claimed their people spread across the whole galaxy. Given the prevalence of humanoids over the entire galaxy, it's not unreasonable to assume that they (or other humanoids following in the footsteps of the ancient humanoids) spread the ancient humanoid "seed codes" for directed evolution even further than the ancient humanoids could. And therefore spreading those common language patterns through most of the rest of the galaxy's humanoids.

Despite all of this explanation, because the UT is primarily for the viewers, some inconsistencies will arise that only make sense with the brainwave-scanning explanation, and other inconsistencies will arise that cannot be explained by either explanation - for example, translations of specific nouns. A missing combadge, as mentioned in the question, is either just plain a mistake (it's where the UT is located), or the alien has their own UT. The Ferengi embed them inside their ears, for example.

Yay storytelling!


Another Simple explanation is that When it comes to humanoid life they were all seeded by an ancient humanoid race 4.5 billion years ago (TNG= THE CHASE) which is why the universal translator has little to no problems in voyager as primary they are interacting with humanoids which despite different evolutionary paths at the end of the day are extremely similar biologically. Compared to the difficulty the translator has towards non carbon based lifeforms. such as the crystaline entity.


The inherent theory behind it is that all intelligent life forms have similar concepts of reference between things. You have objects (nouns), words that describe those objects (adjectives), actions that are done with or too those objects (verbs) and descriptions which modify those objects (adverbs).

While the exact structure and words would vary, an advanced computer using a sample of that alien language should be able to discern patterns and derive a translation matrix from it. Often, a language would be similar enough to a known language to derive quickly. Other times, it may take a long time. There were a couple of examples in Voyager where translating a language took a long while (relatively speaking). That happened with Species 8472 and the Swarm.


This is an extract from this site -- http://en.memory-alpha.org/wiki/Universal_translator

The universal translator is one of many Star Trek technologies that exist primarily as conventions to aid storytelling. The UT enables the vast majority of dialog between characters to be written (and delivered) in English, to the convenience of viewers and writers alike. Writers do not have to devise a new language for each new alien of the week that speaks on-screen, and viewers do not have to watch for subtitles.

Another storytelling conceit is that the device makes non-English speakers appear as if they're speaking English (i.e. lip movements match English language pronunciation). This "convention" is particularly obvious in episodes like DS9: "Little Green Men" as well as ENT: "Unexpected", "Civilization", "Acquisition" and "Precious Cargo", in each of which the universal translator is off-line for periods of time. Were the device real, it would more likely have an effect similar to watching a movie dubbed into another language.

The draft proposal Star Trek is... mentions this concept:

We establish a "telecommunicator" device early in the series, little more complicated than a small transistor radio carried in a pocket. A simple "two-way scrambler", it appears to be converting all spoken language into English. (Roddenberry 11)

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