There are many differences: spellings ("color" vs. "color"), pronunciation ("aluminum"), use of some prepositions ("on the weekend" vs. "at the weekend") and punctuation (putting commas and periods/full-stops inside closing quotations marks vs. outside them). The biggest difference is in slangs and expressions, since those begin from local regions and spread outward over the years—with Britain and the USA being so far apart geographically, it was almost not possible pre-internet to be exposed to new phrases and words from each other's countries.