Tamil-Brahmi does not, however, share the odd forms of letters such as gh in Bhattiprolu. This appears to be an adaptation to Dravidian phonotactics, where words commonly end in consonants, as opposed to Prakrit, where this never occurs. According to Mahadevan, in the earliest stages of the script the inherent vowel was either abandoned, as above, or the bare consonant was ambiguous as to whether it implied a short a or not. Later stages of Tamil Brahmi returned to the inherent vowel that was the norm in ancient India.

According to Kamil Zvelebil,