I heard that a Vietnam draft evader emigrated to the U.K. (England) and reportedly had a ‘slight English accent’ when interviewed in the early 1990’s. (it was a newsprint interview so I could not hear it).
My question is, if the average american adult, at say 21, moved to England, would his accent turn native? If so, how long? Or would it remain forever hopelessly “Colonial”?
He would pick up some English traits but would also retain many American traits. The English would think he sounds American and Americans would think he sounded English.
I’m no expert but from my own experience of such matters I don’t think there’s any straight-forward answer. Some people who move from one community to another in adulthood acquire the new community’s accent, others don’t or only acquire certain aspects of their accent or accents.
I think it would vary depending on the original accent of the “average American adult” and the locale they were moving to as well as the industry they worked in and the company they kept.
I’ve been involved in an online discussion about this recently. There’s a certain American who emigrated to the U.K. when he was 33 and has now lived there for 44 years. Although one can hear a little bit of an American accent in his speech at times, sometimes it sounds thoroughly British. Some of us contend that he must have deliberately forced himself to change it, because usually this doesn’t happen. Usually when someone moves to a new dialect area after the age of 18, their accent doesn’t change very much. Others claim that some people tend to pick up new accents more than others, so this person’s new accent is not surprising.
Before about age 10, if you move from one country to another you tend to keep the accent of your new country for the rest of your life, fully adapting to it, with none of your original country’s accent remaining at all.
After age 10 your accent tends to remain, so when you move it becomes a unique combination of your original and your new accent. Certain words or phrases will have changed definitively, but an underlying remnant of your original accent will always remain, sometimes quite dominantly, sometimes minimally.
The bartender in my local is an American and has lived in England for just over 17 years.
He came here aged 21 and still sounds like a Yank despite all his efforts to acquire an English accent and to talk proper like what I do
I don’t have an accent - everybody else does.
Over time, people do pick up more and more accent traits from those around them - I don’t see why this couldn’t ever - at least in some cases - become a complete transformation, given enough time, deep enough immersion, isolation from original accent influences and no effort to resist the change.
My flatmate’s mum, originally from Yorkshire, now living in Renfrewshire, has a noticeable Scottish accent.
My mother and five younger siblings moved to your city a few years ago and it was fun to watch who picked up the terrible accent and who didn’t.
More relevant than their ages was how out-going they were. My fashion conscious sister picked up the accent very quickly, and dropped it just as fast five years later when they moved back down to home.
My emo brother never really picked it up at all, even though he was younger…
FWIW, I spent a fair amount of time moving arounda s a kid, and when I am around canadians [some friends from Ottowa specifically] they thought I was canadian from Ontario. If I am in the south, I start using the inflections of the people around me and sound southern. Back in new england, I can speak with the darien lockjaw if I am with friends who talk like that.
Some people just tend to blend in =)
It really depends - my Uncle (South African) and Aunt (English) moved from the UK to California some 40 years ago, and by the time I met them for the first time (15 years later), my Aunt had completely lost her accent, and my Uncle retains his to this day. Some people seem inclined to pick up accents, others not.
On the other hand, when I lived in California for a few months, I changed my accent/pronuciation on a few key words to stop the customers in the cafe where I worked from correcting me all the time… “That’s a banana muffin.” “A what? - oh you mean baNAna” "Yes, that’s what I mean… 
"
Grim
How do you pronounce it?
Is there any evidence that women are more apt to try to fit in, accent-wise? II notice that college age kids in Ireland (the lion’s share of whom study in Dublin, the biggest city) come to Dublin and after a few years alot of the women will have either a Dublin accent or a more neutral one while the men far less so.
With the OP’s hypothetical American, while he would certainly pick up traits of English accents, these would also most likely disappear or lessen when he visited back home, or even during phone conversations with people back there. I cannot ever hear any trace of an Irish accent in my mother, except for when she talks to other Irish people, and then it comes flooding back. (Other people insist she’s obviously Irish at all times, though, which shows how imprecise the perception of accents can be.)
I moved from the US to the UK in 1995 when I was 33. My accent is still Iowa bland, but I use British words & phrases (pavement, arse, bollocks, etc).
A friend of mine was born in the Philippines and moved to Houston when fairly young. In her late 20’s she dated a British guy for a bit. After a week in the UK she’d picked up a recognizable Mancunian accent the horror! but it would be gone after a week back in Houston.
My girlfriend’s accent has shifted slightly away from her native Bostonian to English in the two years that she’s lived in London, but it’s only noticeable to me when she meets another American and suddenly I notice the shift back.
Since grimpixie has South Africa in her/his location space, I assume “bahnahnah”, whereas in California, it’s “bahnanah” where the middle “a” is a flat American “a”.
This is what has apparently happened to me. I’ve picked up American word and pronunciation habits but for the most part have kept my South African accent. When I visited family in South Africa many of them claimed that I sounded American, although no American would think I had an American accent.
Exactly. the middle “a” is pronounced heavier, like the “a” in “are”. My Southern in-law family still thinks it is funny how I say that, although I notice I tend to use both pronunciations interchangeably these days.
Bananer?