While it's the same language as American English, there are some key differences:
* Pronunciation: British English has a different accent and pronunciation of words, such as "aluminum" vs. "aluminium".
* Vocabulary: There are some differences in vocabulary, such as "flat" vs. "apartment" or "lorry" vs. "truck".
* Spelling: There are some differences in spelling, such as "colour" vs. "color".
* Grammar: There are some subtle differences in grammar, such as the use of "shall" vs. "will".
It's worth noting that British English is not a single, monolithic dialect. There are regional variations in pronunciation, vocabulary, and grammar throughout the UK.