Complex sentence: "Scotch" applied to people is widely considered pejorative in Scotland, reflecting old Anglo-Scottish antagonisms, but it is still widely used in England and Ireland, and is in common use in North America.
Split into simpler sentences: Scotch applied to people is widely considered pejorative, reflecting old Anglo-Scottish antagonisms. However, "Scotch" is still widely used in England and Ireland, and is in common use in North America.