15Time Lords have their own language
The language of the Time Lords is called Gallifreyan, and is most commonly referenced in the show in its written form of circular shapes (did anyone else think that the language in Arrival looked suspiciously similar?). It's also of course got a spoken form, but thanks to
the language translation tools of the TARDIS anyone we see on the screen will conveniently speak in English with a British (or occasionally American) accent. That hasn't however stopped us from learning a bit about the language.
The modern Gallifreyan language has three different dialects. They are known as the upper dialect, middle dialect, and lower dialect and are divided by society rankings. The upper dialect is spoken by high councillors, royalty, and other high ranks. The middle dialect is spoken by the aristocratic families and nobility, and is believed to be the dialect which the doctor speaks. And finally, the lower dialect is spoken by civilians and the general working population. It all sounds a bit weirdly dystopian to us.