GPT-4 can seemingly make real conlangs. I don't really have a way to test, but when it made one based off romance languages a different copy of GPT-4 could translate it back into English.
<br>Conlang "Vun'kra 2013, Joel t'kara sol'vazh rithan n'zith Austin, Texas, vith'la dvan'zor yal'kei Sarah. Zel'vren, plok'shun krezh'vul Cordyceps t'gol'ka yun'dar, mor'val shu'lan k'vith hurok'zor rithan. Joel, vroth'kei Tommy, vith'la Sarah thun'val zor'kresh, Sarah grol'kei vath'zor rithan n'kara Joel."<br><br>Real "In 2013, Joel is a single father living near Austin, Texas, with his twelve-year-old daughter Sarah. One night, an outbreak of a mutant Cordyceps fungus ravages the United States, transforming its human hosts into cannibalistic monsters. As Joel, his brother Tommy, and Sarah flee the chaos, Sarah is shot by a soldier and dies in Joel's arms."<br><br>Translation "In 2013, Joel traveled to Austin, Texas, with his friend Sarah. During their trip, they encountered a Cordyceps outbreak, which caused a dangerous situation. Joel, along with Tommy, protected Sarah from the threat, and Sarah became very close to Joel as a result."<br><br>It gets a few things wrong and translates it differently each time so I think the names and Cordyceps are doing a lot of the work. So I tried again with a different story that GPT-3.5 wrote.<br><br>Conlang "Tolnai jemir, yorva en kaija nornet Lily, nevri zolma kreska. Hiran vodas nurev kaij, yorvando mestri kolori kon krayonis e markeis. Jemir um, Lily vensa konkurs kreska en skola yor. Yor labora sinfei en kreska yor, adunando omna koro e anima yor en to. Kuan konkurs rezultis anuntaron, Lily esti plena alegra apreni yor vinci prai lok! Yor genitoris esti fiertis yor e pendis kreska vinci yor en frigorifiko pro omnis vider. De jemir ta, Lily savai yor voli esti artist kuan yor kreskis. Yor kontinu kreska e pinta, fina esti artist sukseful e inspirando altri segui somnis lor."<br><br>Translation "Once upon a time, there was a girl named Lily who loved to draw. She would spend hours drawing, experimenting with various colors using crayons and markers. One day, Lily entered a drawing contest at her school. She put her heart and soul into the drawing, adding all her passion and spirit to it. When the contest results were announced, Lily was overjoyed to learn that she had won first place! Her parents were proud of her and hung her winning drawing on the refrigerator for everyone to see. From that day on, Lily knew she wanted to be an artist when she grew up. She continued to draw and paint, eventually becoming a successful artist and inspiring others to follow their dreams."<br><br>Real "Once upon a time, there was a little girl named Lily who loved to draw. She would spend hours each day creating colorful masterpieces with her crayons and markers. One day, Lily entered a drawing contest at her school. She worked tirelessly on her drawing, pouring all of her heart and soul into it. When the contest results were announced, Lily was overjoyed to learn that she had won first place! Her parents were so proud of her and hung her winning drawing on the refrigerator for everyone to see. From that day on, Lily knew that she wanted to be an artist when she grew up. She continued to draw and paint, eventually becoming a successful artist and inspiring others to follow their dreams."<br><br>This is spot on. It's heavily based off romance languages but it seems to have novel elements too.<br>
Spoiler for Hidden:
