Pronunciation of T's in British English

Could anyone tell me more about it? What I have noticed are these patterns:

1) All T's are pronounced and aspirated, even in the middle and at the end of words. This sounds like spitting all the time to me, and I think it's what is considered "posh".
2) All T's are pronounced, but are only aspirated at the beginning of a stressed syllable.
3) T is a glottal stop at the end of a word, the rest of the T's follow either pattern 1 or 2 - (A little bi? of butter)
4) All T's are glottal stops. - (A li?le bi? of bu?er)
5) Some T's are tapped like in American English, but I am not sure of this pattern.

Glottal stops can occur in the positions where Americans would tap their t's, so when I said "all t's are glottal stops" I didn't really mean every T.

Anyone feel like commenting on the features? Thanks

I think JC Wells has identified a pattern (I think mainly among younger people in the south of England) where prevocalic /t/s are tapped like in American English, and word-final /t/s are pronounced as a glottal stop (at least before a pause).

There's also the phenomenon where, if one word ends with a "t", and the next starts with a vowel, the "t" moves to the next word. E.g. "i' tis" instead of "it is", "a' tall" instead of "at all".

<<E.g. "i' tis" instead of "it is", "a' tall" instead of "at all". >>

That should be included in 1) in my first post. All the t's are aspirated, even at the end, so "a tall" and "at all" would be pronounced the same. I guess this is part of posh accents, isn't it?

When the 't' is at the end of the word, or in the middle, it can be pronounced as a glottal stop (this is by no means correct, but everyone does it) - by the way, the plural of 't' is 'ts' or 't's = never t's. The apostrophe is only for the genitive case, or for an abbreviation.

<<That should be included in 1) in my first post. All the t's are aspirated, even at the end, so "a tall" and "at all" would be pronounced the same. I guess this is part of posh accents, isn't it?>>

I'm not so sure about that - I think even regular British people, who generally have word-final glottalization, use that pronunciation too - I think this is a specific lexical case where the phrase "at all" has been reanalyzed phonemically as /@"tO:l/.

<<(this is by no means correct, but everyone does it)>>

There's no question of correctness here - it's just dialectal phonology.

No, the apostrophe is used for literals. "This book has 200 pages" means that there are 200 sheets in the book. "This book has 200 page's" means "there are 200 instance of the word 'page' in this book".

Well, that's an incorrect use of an apostrophe. If you want to refer to the number of instances of the word page, you use quotes around the whoe word, and probably wouldn't choose such ambiguous phrasing anyway.

Yeah, if I saw, "This book has 200 page's", I would just consider it an error.