Old Orthography

"The da drag, or ‘strong da’ was a standard feature of Old Tibetan orthography. A final da syllable often followed a nga, ra or la, so that for example we have gyurd (which later becomes gyur) and pheld (later phel). Initally the da drag may have been a fundamental element of grammer. If so it had lost this aspect by the time of the earliest extant documents. The da drag appears in the ancient grammatical treatise ascribed to Tönmi Sambhoṭa, The Thirty Verses, but no grammatical role is assigned to it there. More importantly, the da drag had a phonetic role indicating the way the nga, ra and la were pronounced when followed by certain other syllables. This can still be seen in Classical Tibetan. When the statement particle –o follows a consonant, that consonant is normally reduplicated; for example, yin no and byung ngo. But some syllables which orginally had the da drag act as if they still have it; for example when –o is added to gyur it becomes gyur to. Thus the da drag lived on as a phonetic element after its disappearance from writing."

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