'n' is a common symbol for 'unknow number' in the maths textbook,
N年前 = so many years ago/ unknown number of years ago
N樣嘢 = so many things/ unknown number of things
I did wonder why use 'n' but not X or Y for unknown numbers? Then I thought, oh, the word 'number' starts with an 'n'
I also wondered since 'n' can be a small number, why we use it for numerous, ...
It means 'numerous/several facts about Fuku Noodle'.
The slang N has an algebraic etymology which denotes an unspecified but large number (e.g., 1, 2, 3, ..., N). Apparently this emerged in the early eighties (see more here).
件 is the counter for 事 ('a thing; a matter', here its meaning is fairly abstract and dummy-like, meaning whatever that is about Fuku ...
Searching 番薯 doesn't show any slang/insult-related result.
When I hear people say 成嚿蕃薯噉 (being dumb), I imagine 蕃薯 was food for poor people who couldn't afford rice. Due to the typical stereotype of rural farmers who were mostly poor, and the presumption of poor people were less intelligent, the term 蕃薯 was linked to dumbness by association with the poor
i suspected that it’s the influence of a comic called “old master q” (老夫子)
one of the main characters is named “big potato” (大蕃薯), a short, fat, and; stupid guy.
one might guess the rest, from such stereotype 😸
The Gan-Hakka hypothesis is most famously put forward by Sagart (2002), based on certain unique shared innovations in both Southern Gan varieties and Hakka:
屋下 as the usual word for "house", compared to Cantonese 屋企.
Use of 倈/孻 (beginning with /l/) as the usual word for "son".
Similar words for "here" and "there" ...
Here, 果 is just an alternative representation of go2 (meaning that, more commonly written as 嗰, functioning similarly to Mandarin 那), since some variations of Cantonese pronounce Jyutping kw- and gw- as k- and g- (notably under the influence of phonetic changes known as 懶音).