Formal English is used when we need to express a polite distance between participants in formal situations such as debates and official ceremonies (speech) or formal documents and letters (in writing style). Formality in recognised in choices of pronunciation (only in speech), grammar and vocabulary.
I should like to extend a warm welcome to all guests tonight.
Compared to more informal:
I want to welcome you all here tonight.
Seeking permission:
Would it be possible to…?
I wonder if you could…
Do you mind if…?
Granting permission:
By all means do…
Please donʼt hesitate.
Yes, certainly, you can.
Refusing permission:
I donʼt really think you can.
Iʼm afraid thatʼs not possible.
Iʼm sorry Iʼm not supposed to allow…
In formal conversations or monologues, speakers organise their discourse marking the openings and closings the topics. Discourse markers are specific words and structures to mark boundaries between one topic and the next and help with the planning and organisation of speech.