
Again, the /t/ is not entirely dropped - it's replaced by another kind of stop, further back in the throat, called a 'glottal stop' (or sometimes just 'a glottal' - a singer, for example might say something like 'Do you think I should separate those two words with a glottal?')
The glottal stop is widespread, is typical - for example - of Estuary English, and is even finding its way into the speech of people known for using
RP.
I don't use it in a word like 'forgotten' (I explode the [t] nasally), but my sister does and my daughter does - so it's not necessarily a regional thing (although there
are regional dialects where a glottalized /t/ is the norm).
b