Letter on position 1 (p) changed: 7 words burs curs furs gurs lurs nurs ours Letter on position 2 (u) changed: 2 words pars pirs Letter on position 3 (r) changed: 9 words pubs puds pugs puls puns pups puss puts puys Letter on position 4 (s) changed: 4 words pure puri purl purr