Gauss's papers were originally written in Latin.
Yes, there are several English translations of Gauss's papers available.
You can find English versions of Gauss's papers in online databases, such as JSTOR or Project Euclid, or in libraries that have a collection of scientific literature.
No, not all of Gauss's papers have been translated into English. However, some of his most influential works, such as "Disquisitiones Arithmeticae" and "Theoria Motus Corporum Coelestium", have been translated.
The accuracy of English translations of Gauss's papers can vary depending on the translator. It is always best to consult multiple translations or refer to the original Latin versions for the most accurate understanding of Gauss's work.