There are many diffferences. A few that I can think of are: 1. Spelling. Americans write "labor"; the British write "labour." 2. Vocabulary. Americans say "cookie"; the British say "biscuit." 3. Grammar. Americans love the subjunctive ("It is important that you BE here on time"); the British use the subjunctive, too, but sometimes they would express that sentence in another way. They also differ on prepositions sometimes. Americans might be busy ON the weekend, while our British friends might be busy AT the weekend.