Growing up I called it a Settee, but seem to have slipped into some West Yorkshire lingo and now call it a Sofa.
Back in the 1950s, the author Nancy Mitford wrote a guide to words that were suitable for the aspiring upper class, and words that were used by the aspiring middle class. According to Mitford, the upper class tended to use simpler terms, similar to the working classes, whilst the aspiring middle class would opt for more pretentious language. In terms of sofa, Mitford suggested that ‘sofa’ was the correct term, whilst ‘couch’ and ‘settee’ were the more pompous terms used by the aspiring middle class.