BRITS: Why do you pronounce R's in words which don't have them?

Question

Like "I'm drawRing a picture of my mum."

Answer 1

This type of pronunciation is also found in Australia, New Zealand and even the northeastern United States. The other day I heard a New Yorker say "ar-topsy" for autopsy.

This is actually an accent difference not a dialect difference. Nobody knows exactly why these kinds of changes occur but one theory is that the human ear is an imprfect mechanism for hearing and we don't all hear sounds the same way. Also, William Labov did some studies in the 1990's which indicate that the dominant person in a community sets the pronunciation standards of that community. Over time, everybody else in the region will immitate his (or her) pronunciation.