American vs British English: what actually differs
American and British English are close enough that speakers understand each other without effort, but the differences are real and consistent, not random. Mixing them (British spelling with American vocabulary, say) reads as inconsistent rather than bilingual. Here is what actually varies, and why picking one variety to learn matters more than people think.
Spelling: -our vs -or, -ise vs -ize, doubled consonants
British keeps a French-derived -our (colour, favourite) where American simplifies to -or (color, favorite). British favours -ise (organise, realise); American consistently uses -ize (organize, realize). British also doubles some final consonants before endings that American does not: travelled vs traveled.
Vocabulary: same thing, different word
Plenty of everyday nouns simply differ: flat/apartment, lift/elevator, pavement/sidewalk, rubbish/trash, trousers/pants (which means underwear in British English, a classic mix-up). These are not spelling variants; they are genuinely different words for the same thing, so they have to be learned as vocabulary rather than deduced from a rule.
The gotten question
American English uses gotten as the past participle of get (I have gotten better); British English uses got for both past simple and participle (I have got better). It is one of the few places the two varieties genuinely split on verb forms rather than just spelling or vocabulary.
A few grammar habits
British English treats collective nouns as sometimes plural (the team are winning); American keeps them singular (the team is winning). British favours the present perfect for recent events (I’ve just eaten); American often uses simple past instead (I just ate). Neither is wrong; they are dialect defaults.
Pick one and stay consistent
Picking a target variety and sticking with it matters, since mixing signals shows up more in writing (exams, job applications) than in speech. Verboteca ships American and British English as separate tracks with their own spelling and vocabulary throughout, so what you practise stays internally consistent.