How many accents are there in mainland Britain?

There are so many accents in the UK that almost every town has a slightly different accent. Let's say there are many different accents in a COUNTY that just all sound the same to outsiders! However, there's no such thing as not being able to relate to each other, except for a very, very few people with very, very heavy accents.

Besides English, there are several completely different languages spoken in the UK, namely gaelic (in NW Scotland) manx (in the Isle of Man), welsh (in Wales) and cornish (in SW England). All of these languages belong to the Celtic group and are not related to English. There is also scots (in southern Scotland). scots has some **** same vocabulary as English, but is now considered a different language.

Everywhere in the UK has an accent that doesn't resemble American English, but I think due to immigration, the American accent was influenced by the Irish and northern Scottish accents.

There are also vocabulary differences between British and American English that can easily lead to misunderstandings. For example-

car boot

American English- trunk

English- boot

tap

American English- faucet

English- tap

There is also the word pants which has different meanings in the UK and the US. In the UK it means underwear and in the US it means pants!