Nobody knows if the Star Wars characters speak a language totally identical with Modern Twentieth Century (Fox) English, or if the Star Wars movies show actors speaking English translations of a very different Galactic Basic language. But I think that there are strong reasons that to deduce that Star Wars Galactic Basic is translated into English in the Star Wars movies and doesn't really sound like English.
Decades and centuries ago, it was common for works of fiction to include frame stories for the purpose of, among other things, explaining how the writers learned of the events in the stories, explaining the transmission of the "historical" knowledge down to the readers.
That is no longer fashionable in fiction.
But when I read or watch fiction, I always more or less pretend while doing so that the events are real and nonfictional, and I assume that all other readers or viewers also do that.
If fictional events are nonfiction inside the fictional universes of their stories, that means there is a chain of transmission of the knowledge of those fictionally historic events down to the reader or viewer.
When you read a history book or watch the news on television, information about those (mostly) real events has passed through a chain of transmission to you, even if you don't know any details about that chain of transmission.
So while enjoying a work of fiction, I always assume that it has a frame story explaining the chain of transmission of the knowledge of the events to me, even though the frame story is not given and even the writers of the story probably never gave it any thought. Therefore I can only guess about the possible details of such a frame story.
In a fictional universe where Star Wars is true, the real world still exists for us, and our planet Earth is certainly not currently in open and public communication with the galactic society depicted in Star Wars.
So anyone who suspends disbelief in Star Wars has to imagine that there has been some more or less secret communication of some type between the Galactic society of Star Wars and our own society on Earth. And there is not much evidence for them to decide what form that communication took.
In Star Wars it is "possible" that some Force using observers observed and recorded all the events depicted in Star Wars movies (and maybe other media). And somehow George Lucas & various associates here on Earth gained access to those recordings and converted them directly to film using some mechanical or electronic or Force using method. In that case just about everything in Star Wars should be literally true and correct, including in the case of this question Galactic Standard sounding like 20th Century English.
But it is also "possible" that somehow a galactic history book from the Star Wars Galaxy arrived on Earth somehow, and that George Lucas found it and thought that there were a lot of good movie plots in it, and wrote scripts more or less faithful to the history book, got studio funding, higher actors, built sets and props, etc., etc., and filmed a bunch of movies that were more or less accurate in plot, visuals, and sounds, etc. Obviously in this case it would be possible for the movies to vary from the true events a lot more, including having the actors speak in English more or less translated from Galactic Standard instead of in the alien language of Galactic Standard. And probably also in hiring Human actors without any alien makeup to portray the main species in the Star Wars society, even though that species probably does not look identical to Earth humans.
And since a lot of people claim publicly that they worked on various aspects of Star Wars movies that second possible explanation of how knowledge of Star Wars reached Earth seems to have a lot more evidence in favor of it.
And it would seem that a similar explanation is necessary for Star Trek, but with some differences. For example, Star Wars happens in "a galaxy far away", which should be at least tens of times, and possibly many millions of times, farther away than most events in Star Trek happen. So the knowledge of Star Wars events has had to travel much farther to get to Earth than the knowledge of Star Trek events, and thus is somewhat harder to explain.
However, the time factor makes the knowledge of Star Wars events much easier to explain than the knowledge of Star Trek events. Star Wars happens "Long, Long Ago", so there is no time travel necessary to explain how Star Wars knowledge reached the here and now, merely space travel. But Star Trek is set in the future, and probably in the future of an alternate universe, so the explanation for knowledge of Star Trek events has to explain how the knowledge traveled back in time to our era, and probably also traveled sideways in time to our timeline.
So my preferred explanation for the relationship between the Star Wars society and our society involves knowledge of Star Wars events arriving on Earth somehow and being the basis of the scripts for the Star Wars movies which are filmed on Earth with Human actors, and thus the actors speak English translations of the Galactic Basic words the characters spoke. So in my opinion the words you hear in Star Wars are English translations of the Galactic Basic words and Galactic Basic is very different from English and other Earth languages. (and the main species in the Star Wars galaxy probably doesn't "really" look identical to Earth Humans.)