These are transcripts of Boris Johnson speaking taken from people putting them up on twitter - 'Josh linguist', Liz Stokoe and Sally Luxmoore. Please click on them to read them as I don't know how to make them bigger. Sorry.
Some people think that 'sounding posh' = speaking correctly. These transcripts of Boris Johnson speaking illustrate how even the poshest hesitate, revise, repeat, produce incomplete sentences etc. when they/we *speak. Speech and writing are different. When we say that we want children to learn standard English, this is about leaping from spoken English to written. Modelling written English on spoken English is counter-productive. Immersion in the standard English of children's books through reading widely and often is better. This is one of the things that underpins 'reading for pleasure' - browsing, choosing, sharing and talking about books that you want to read.
