Everybody’s Cantonese

I’ve been going through an old book entitled Everybody’s Cantonese (1949, by Chan Yeung Kwong), and although the vocabulary is pretty basic, I did find some old pronunciations and interesting characters. For example, 咁 is transcribed as gom3, with a back rounded vowel (nowadays usually pronounced gɐm3); and 粒 is transcribed as nɐp5 (which I’ve always heard as lɐp5). These appear to the old pronunciations which have gone out of fashion.

Interesting characters include 氈 dzin1 ‘blanket’, 笪 daːt3 ‘classifier for places’, 樖 pɔ1 ‘classifier for trees’, and 擸𢶍 laːp6saːp3 ‘trash’ (now usually written 垃圾). I’ve always wondered about the word for trash, which in mainland Mandarin is pronounced la1ji1, but in Taiwan is pronounced le4se4. Why the difference? Are one or both of the variants related to the Cantonese word, and how?