I am interested to learn whether the changes in Hong Kong pronunciation of Cantonese came about, was it because the English in Hong Kong had difficulty understanding the Cantonese?
For instance, I have started to learn Cantonese from CDs and found that the word for "I" which I thought to be pronounced something like "gnaw," always sounded like "no" to me and in my mind set up an expectation of a negative expression; and then I would have to reverse my thinking that it was not.
I guess see where a lot of misunderstanding between English speakers in Hong Kong and the Cantonese speakers might lead the native speakers to alter their speech to be better understood?
Since I am not a linguist, any answer using terms unique to linguistics will not be helpful to me.