Gallifreyan (the lost language of the time lords)

Gallifreyan (language)

There were several forms of written Gallifreyan. By the time of the Doctor, the archaic Old High Gallifreyan language used in the days of Rassilon had changed considerably. (DW: The Five Doctors) The later "vulgate" was presumably the Doctor's native language.
Examples: Old High Gallifreyan

The phrase "Hello, Sweetie" in Old High Gallifreyan.

Old High Gallifreyan was the ancient language of the Time Lords. It was not known by many; by the Doctor's era, it was virtually extinct, superseded by modern Gallifreyan. The Eleventh Doctor claimed that Old High Gallifreyan once possessed immense power when correctly harnessed, such as raising empires or destroying gods. The written form of Old High Gallifreyan resembled, to human eyes, a mixture of Greek letters and mathematical symbols.

A page of The Worshipful and Ancient Law of Gallifrey.

• Inside the Tomb of Rassilon in the Death Zone on Gallifrey, an old rhyme was written in "Old High Gallifreyan," which explained the outcome of the "Game of Rassilon".

This text included the letters δ³Σx², which was given as the Doctor's name in the 1972 behind-the-scenes book The Making of Doctor Who by Terrance Dicks and Malcolm Hulke.

• Within the Doctor's rooms on Gallifrey there was a painting of a woman holding a scroll with the words "Death is but a door" written in High Gallifreyan.
• The First Doctor wrote his Five Hundred Year Diary in High Gallifreyan to make sure no one else could read it.
• River Song could write in Old High Gallifreyan.
• The word "valeyard" is said to mean "learned court prosecutor."
• "Mi’en Kalarash" translated as "Blue Fire."

In The Time of Angels, Amy asked what some writing in Old High Gallifreyan meant, implying that the TARDIS did not translate it. River Song, in A Good Man Goes to War, confirmed that the TARDIS did not translate Gallifreyan.

Modern Gallifreyan

An example of Gallifreyan script written by the Fourth Doctor.

While Old High Gallifreyan was the original language of the Time Lords, it had evolved into a different form by the time of the Doctor

• Two Time Lords looked at an archive of information on the Third Doctor, which displayed a photo and writing in modern Gallifreyan.
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• A vaguely Arabic-looking script, in a letter written by the Fourth Doctor to warn the High Council of an assassination, was in modern Gallifreyan.
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• The Seventh Doctor left a note for the Supreme Dalek in a script other than English. This included the Doctor's "name" (Theta Sigma) in Greek.

Circular Gallifreyan 

An example of the interlocking/overlapping circles.

• A complex system of interlocking circles was used by the Doctor's TARDIS output screens in "coral desktop theme" mode and was seen in the notes that the Doctor scattered around the console room. (DW: Rose onwards) Earlier, the TARDIS' displays had appeared in English. 
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• Simpler handwritten circles appeared on the Betamax tape used by the Tenth Doctor to trap the Wire. The circular text, since scribbled over, presumably stated the tape's contents.
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• The Visionary wrote interlocking circles, which Rassilon and the other Time Lords could understand. One of the words was "Earth."
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• Text in circular Gallifreyan was seen carved into the Doctor's cot. It was implied that this writing was his name.