Speaking English

George Bernard Shaw expressed it this way: "England and America are two countries separated by a common language" When I first arrived here, I had thought of adopting an English accent. Within 10 minutes I gave up. Though there is a certainly an accent distinguishable from Australia, America, New Zealand, etc., there is not one English accent. In four months I have identified several different native accents. And of course each immigrant brings in their own flair and adaptation. One of the major signs of being a foreigner is now simply how you say something, but what you say-your vocabulary. Most languages function this way, difference in sounds and words: Spanish in Spain and Spanish in Mexico, English here and the US, etc. but what is amazing is to see the variety within a country or region: southern France, northern France. Though this all might seem obvious, it is easy to forget, especially when you come in speaking the same language.
Actors know all too well that accents are not everything. A simple accent and phrase here or there might earn you some points, but your delivery will be seen as mere imitation until you learn and adopt new vocabulary. I have some theories about why British actors find it easier to adopt an American accent than Americans a British one, but i'll stop that tangential stream here.
Accents in general are fascinating to consider. Urban areas tend to speak faster than rural areas, with some natural consequences. For example the slow "drawl" or "twang" heard in the southern states compared to the speed of Washington DC; or the more open, round tone of the Australian Outback compared to Sydney. I don't think it unfair to read something into the values this reveals in each community.
I am still learning to distinguish the various regional accents, helpfully shown in the graphic here. As I get out of London more, i hope to hear and identify these however feebly. Disclaimer: I am not a linguist, never have been and completely fulfill the stereotype of Americans being monolingual. I am surrounded by the South Asian community, so when I speak on my experience with "English, English" it is limited. When I travel, I tend to be a silent observer and catch things occasionally people watching. This list could obviously be huge but I thought I'd just include a portion of the things I've noted thus far, and admit "off the bat" that most of these are not set in stone but simply perceptions I have:
(USA-English)
food:take out/to go-take away, check-bill, dessert-pudding or sweet, fries-chips, chips-crisps, candy-sweets, cookies-biscuits (sweet), crackers-biscuits (savory), roast-joint
around home: yard-garden, window-glass, coach-sofa/settee, flashlight-torch, trash-rubbish,
grocery store-market: toilet paper-toilet roll, paper towel-kitchen roll
clothing: pants-trousers, sweater-jumper,
around town: line-queue, friend-mate, cell phone-mobile, sidewalk-pavement, billboard-poster,
car: trunk-boot, hood-bonnet, windshield-windscreen, gas-petrol, yield-give way, detour-diversion, parking lot-car park, 2 way street-dual carriageway, highway/turnpike-motorway, fat tire(tyre)-puncture
one i made up but some mates liked: sanitation engineer for rubbishman, "trashman"
misc: fired-made redundant, study-revision (to revise), doc's office-surgery, college-University (uni), resume-CV, field-pitch, soccer-football, game-match, restroom/bathroom-WC, loo, toilet, bog, garderobe (each has distinctions), napkin-serviette and excuse me-pardon are used but avoided with middle/upper class

pronunciation:
a in the middle of a word is often "ah"-tomahto, vahz, etc.
"z"-zed, "h"-HAYtch, vitamin-VITTamin
t,d-clear t, almost carried over to next syllable,or creating a new one "but-ter", God=Gah-t

emphasis:
weekEND, conTROversy, fruSTRATing,

general observations:
-upper class drop vowels so to write it out it would look like a text message, Birmingham-brmnhm, handkerchief-hnkrchf
-lower/working class drop their consonants, handkerchief-'ankercheef, kettle-ke'le
th-f, teeth-teef, thing-fing
ending/final g's become ks-everyfink, nuffink

normal English understatements:
beware!-mind
I hate it!-I find it unpleasant, uncomfortable,
horrible-not recommended, unfortunate
gory or disgusting-fairly graphic, slightly disturbing
when talking of people, "very" is excusable but "rather" is preferred all around

general rules:
-crunch your words
-"z" is suffixes are "s"-realised, idealised
-a "c" between 3 vowels is eliminated- leicester-lester, gloucester-gloster
-w following a consonant and leading a second syllable is often eliminated-warwick, chiswick
-old English places adjectives after nouns or pronouns-park royal, river thames