For example, the protagonist of C. S. Lewis's novel Out of the Silent Planet is able to use his training in historical linguistics to decipher the language spoken on Mars.
The existence of alien languages and the ease or difficulty of translation is used as a plot device or script element in a number of franchises, sometimes seriously, and sometimes for comedic value.
In the Star Wars universe, for example, this language is known as Basic and is spoken by the majority of the characters, with a few notable exceptions.
Other alien species take advantage of their unique physiology for communication purposes, an example being the Ithorians, who use their twin mouths, located on either side of their neck, to speak in stereo.
Similarly, in Stargate SG-1, the protagonists encounter a galactic meeting place where different races communicate with one another using a language based on atomic structures which is "written" in three dimensions rather than two.