There is also the matter of "prestige dialect" -- and of "register" (I may be using archaic linguistic terms.)
Here in the USA it is not prestigious to pronounce "creek" as /krik/. As an English teacher and a graduate of Harvard I know that only too well, and yet I cannot bring myself to pronounce it the way people from a city would.
In my dialect we have a second person plural pronoun -- "you'unz" -- which is almost toxic to the ear of many people and utterly unprestigious. But I like to point out that it solves a problem with English that has to be dealt with otherwise paraphrastically e.g. "all of you" or "you students".
I shift my register a little when I am teaching. If I am sitting down and talking to a lawyer, I shift it a lot.
I am not sure if I have already mentioned it in this forum, but I care enough about my dialect that I at times use my own spelling system for writing it. I call it "Artok Ruy'n", which transcribed into Standard English would be "Our Talk Writing" (or "speech")
Dear .... Taghavi,
I think now you realise the differences...however, let me give you this examples of dielects and accents from our own country. You see Turks and Guilaks speak Turkish and Guilaki both of which, in our country are considered as dielects, as they have slightly different structures and different lexicons...Yet, the Turkish spoken in Tabriz is different to that spoken in Ardabil, not due to a difference in the lexicons or structures, but the way the people pronounce words, put stress on specific items, or speak more explosively,...etc. People having different accents won't have problem understanding each other...hope this helps...