2. Vowel differences: One of the biggest differences between British pronunciation and American pronunciation lies in their pronunciation of voiced vowels (schwa,/? /) processing. In English, voiced vowels often appear in some monosyllabic unstressed short sounds A (such as about) and er (such as computer).
Er in American English is rarely voiced, and sometimes voiced vowels are used for short sounds I (such as sentimental and realistic) and U (such as wuss), and even short sounds oo (such as hooker). The pronunciation of voiced vowels is uncertain, but it almost sounds like a rapid pronunciation between "Russian" and "ah"
3, consonant differences: the letter R simply represents all the differences between Britain and the United States, everywhere. When pronouncing consonants, the difference is that when R is at the end of the first word and the second word begins with a vowel, British English will pronounce R as the consonant of the vowel at the beginning of the next word, while American English will read it alone and still pronounce the original rolled tongue /r/.
Extended data
It has only been more than 300 years since English really became the language of Americans. As we know, modern English developed from the Anglo-Saxon dialect in southern England around 1400. There are also many words borrowed from the French spoken by the Normans who conquered England in 1066.
Wales, Scotland and Ireland were different countries at that time. The language spoken by people is Celtic. At that time, Europeans didn't know there was North America at all; Therefore, the language used by European scholars is Latin, and English has really become the mother tongue of the British for about 300 years.
Baidu Encyclopedia-American English