There are lots of words which Simon pronounces like us, but here are a few others which make me smile:
"tripesy" for "stripey"
"pum out!" for "come out!" (at the end of a meal when he wants to get down from his chair)
"boy-ding" for Bob the Builder
"fanky much" or just "much" for "thank you very much"
And after "fleeping" all night, he gets up in the morning and helps Papa to make "polledge"
He also makes a classic mistake for a child learning French as a mother tongue, which is that because his Papa asks him "Tu veux que je t'aide?", if he wants help he says, "T'aide!" ... but also being an English-speaking Postman Pat fan, he then makes a different link and says, "Ted Glen!" the name of the handy-man in PP.
He also does a very good impression of Iggle Piggle from In The Night Garden ... but don't most two year olds?!