Not surprising, considering that today’s Cantonese is much closer to ancient Chinese than Mandarin. Though it’s a fact that most knee-jerk northern chauvinists would deny at the drop of a hat, Mandarin is a phonetically impoverished cousin of some southern dialects such as Cantonese or Fukienese. Cantonese has 7-8 tones to Mandarin’s 4-5, and retains sounds such as k,m,p and t at the end of some syllables. Over the centuries Mandarin was strongly influenced by the ruling Mongols and the Manchus who apparently had difficulty reproducing these sounds and tones, and so they were gradually lost.

I remember my poetry teacher in Taiwan — who was actually a northerner from Henan, but who had learned Cantonese while teaching in Hong Kong — reminded me that whenever we read Tang Dynasty poetry, if it doesn’t rhyme in Mandarin, try it in Cantonese. In which case, it often does rhyme, a further indicator of the dialect’s more ancient roots.