What's the difference between sofa and couch?
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A sofa has arm rest, were a couch does not. After WW2, a lot of GI's could only afford a couch, but would buy the arm rest at a latter day. That is way a lower income person would be a called a couch potatoes, for lack of motivation. Sofas were higher priced. Who has ever heard of a sofa potato?
I liked this answer I came across: The couch/sofa example is different, I think. It's true that there are many ways of framing the semantic (or at least pragmatic) difference between couch and sofa (e.g. a sofa seats 4 and a couch 3), but I sense a consensus is emerging at least around here (the Midwest) in which sofa is defined as a nicer / fancier couch. This is easily confirmed by the fact that furniture stores only advertise sofas. I've never seen a couch advertised (except in the classifieds) even by the low-end furniture retailers. Seems to make sense to me. Oh, sofa comes from suffa in Arabic -- and a divan has no back, just cushions against the wall, but sofas usually do have backs, but do not necessarily have beds in them, those are sleeper-sofas.
