structural:scholar_edition, information:classification
Tonal H letter

The presence of an (although the is now silent or very weakly pronounced except word-initially) word-finally (and sometimes medially) often causes a rising tone before it, for example cá(h) "tea".

The Gurmukhi script which was developed in the 16th century has separate letters for voiced aspirated sounds, so it is thought that the change in pronunciation of the consonants and development of tones may have taken place since that time.

Some other languages in Pakistan have also been found to have tonal distinctions, including Burushaski, Gujari, Hindko, Kalami, Shina, and Torwali, though these seem to be independent of Punjabi.