Hi, Sharon! I don't mean to insult you but as a native, I would like to point out that "nei5" is the ONLY ONE that is correct ("nei", not "neih") and I am curious about your answer. Some Chinese words do have more than one correct pronunciations but this is not the same case for "nei5". "Lei5" is very common among native Cantonese speakers but it's incorrect (many of them don't know about this at all), with no doubt. Look it up in a dictionary and you will find out. A frequently-occurring mistake is still a mistake, even though you would understand what they actually mean. Proper is proper. You don't find properness just in the field of education and I don't know why you used quotation marks with the word "proper" in your answer. Technically, "nei5" and "lei5" are two completely different words, just like "lap" and "nap", "line" and "nine" in English Frankly, I have never read the book you mentioned so I cannot judge whether everything the authors suggest is correct. However, first, I can't see any reason why you had to cite a book about "comprehensive Chinese grammar" to talk about a pronunciation matter. Second, why would you use a book written by a foreign author who is not native Cantonese speaker? (Mr. Matthews is a renowned linguist though)

Lay ho ma ? > How are you ? You good come ?/ Lay ho mole > Are you good or not? If you pronounce it as just "Lay" , it will be understood. Trust me on this ) Mole pronounced with a sharp falling tone means "or not" at the end of a question .