Hello! I was pleased to discover your blog, seeing as the question of the language used by Gems puzzled me since we've met those from Homeworld. My headcannon is that Steven (and by extension the viewer) is able to understand e.g. Peridot's speech at first due to his heritage; Peridot talking with Greg later would be an assessment of her kind's enhanced linguistic skills, but it entails that no one in Beach City would have been able to understand YD's speech. What is your take on this?
First of all, thank you for the compliment. Second, I have two theories on this subject:
1) Gems have been present on Earth for at least 5750 years (as Garnet says in “The Answer”), and probably longer, and affected human development - as Tumblr user slythwolf puts it, “Garnet doesn’t have a British accent, Britain has a Garnet accent.” Peridot’s transmission was intelligible to ordinary Beach Citizens, so we know that their language has remained mostly unchanged from its human-influencing roots, which I am willing to allow given their stratified society.
2) Gems have used said enhanced linguistic skills to prepare for missions, possibly having learned human languages after Lapis Lazuli’s flight back to Homeworld or possibly using translator devices, and communicate in English in order to better make their might understood to the daureth.