The old testament was translated from Hebrew, the Language at the time of the Jews. However, after 70ad they compiled the OT as we know it, without certain books (the apocrypha). The LXX (Septuagint / Dead Sea Scrolls) was a copy of the OT converted to Greek before 70ad. This was the book the Apostles read and preached from. Keep in mind the New Testament was written in Greek.
For those who study there bible allot, you may have noticed certain old testament quotes by the Apostles that were not exactly word-for-word when you read the old testament parallel passage. This is because our bibles have the Greek New Testament and an Hebrew Old testament that was complied after 70ad.
This is a huge point, through what authority were the other books rejected as scripture?
Though I write this, I do believe that what we call our bible today with all it various English translations is more that adequate for faith. I do believe there are additional early church manuscripts that should be referenced to understand the new testament church doctrine as well. We make too many assume of what the early Church leader meant by certain scripture without going to reliable sources, Like Clement of Alexandria and Polycarp, and other early church fathers. Instead we rely on the Teacher of our time to interpret. Not smart